CENX / Century Aluminum Company - SEC申報文件，年度報告，委任書

$MM (except shipments and per share data) Q1 2026 Q4 2025 Aluminum shipments (tonnes) 122,865 140,257 Net sales $ 649.2 $ 633.7 Net income attributable to Century $ 337.5 $ 1.8 Diluted earnings per share attributable to Century $ 3.23 $ 0.02 Adjusted

Exhibit 99.1 Century Aluminum Company Reports First Quarter 2026 Results Chicago, May 7, 2026 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its first quarter 2026 results. First Quarter 2026 Financial Results $MM (except shipments and per share data) Q1 2026 Q4 2025 Aluminum shipments (tonnes) 122,865 140,257 Net sales $ 649.2 $ 633.7 Net income attributable to Century

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 7, 2026 Century Aluminum Comp

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 7, 2026 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File N

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2026 ☐ TRANSITION REPORT PURSUANT TO

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2026 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-34474 C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) ☒ Filed by the Registrant ☐ Filed by a Party other than the Registr

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) ☒ Filed by the Registrant ☐ Filed by a Party other than the Registrant Check the appropriate box: ☐ Preliminary Proxy Statement ☐ CONFIDENTIAL, FOR USE OF THE COMMISSION ONLY (AS PERMITTED BY RULE 14a-6(e)(2)) ☐ Defin

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) ☒ Filed by the Registrant ☐ Filed by a Party other than the Registrant Check the appropriate box: ☐ Preliminary Proxy Statement ☐ CONFIDENTIAL, FOR USE OF THE COMMISSION ONLY (AS PERMITTED BY RULE 14a-6(e)(2)) ☒ Defin

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 2, 2026 Century Aluminum Co

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 2, 2026 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File

CENTURY ALUMINUM COMPANY Subsidiaries of the Registrant Company Name State or Other Jurisdiction of Incorporation or Organization Name Under Business is Conducted Century Aluminum of South Carolina, Inc. Delaware Century Aluminum of South Carolina, I

EXHIBIT 21.1 CENTURY ALUMINUM COMPANY Subsidiaries of the Registrant Company Name State or Other Jurisdiction of Incorporation or Organization Name Under Business is Conducted Century Aluminum of South Carolina, Inc. Delaware Century Aluminum of South Carolina, Inc. Century Aluminum Sebree LLC Delaware Century Aluminum Sebree LLC Century Marketer LLC Delaware Century Marketer LLC Century Californi

POWER OF ATTORNEY

EXHIBIT 24.1 POWER OF ATTORNEY I hereby constitute and appoint John DeZee and Paul Sharobeem as my true and lawful attorney-in-fact and agent, with full power of substitution, for me and in my name, in any and all capacities, to sign on my behalf the Annual Report on Form 10-K of Century Aluminum Company for the fiscal year ended December 31, 2025, and any amendment or supplement thereto; and to f

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE FISCAL YEAR ENDED DECEMBER 31, 2025 ☐ TRANSITION REPORT PURSUANT TO SECTI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE FISCAL YEAR ENDED DECEMBER 31, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number 001-34474 CENTURY ALUMINUM COMPANY (Exact name of registrant as specif

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 12b-25 NOTIFICATION OF LATE FILING

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 12b-25 NOTIFICATION OF LATE FILING (Check one): ☒ Form 10-K ☐ Form 20-F ☐ Form 11-K ☐ Form 10-Q ☐ Form 10-D ☐ Form N-CEN ☐ Form N-CSR For Period Ended: December 31, 2025 ☐ Transition Report on Form 10-K ☐ Transition Report on Form 20-F ☐ Transition Report on Form 11-K ☐ Transition Report on Form 10-Q For the Transition Pe

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 19, 2026 Century Aluminu

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 19, 2026 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission

Q4 2025

Exhibit 99.1 Century Aluminum Company Reports Fourth Quarter 2025 Results Chicago, February 19, 2026 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its fourth quarter and full year 2025 results. Fourth Quarter 2025 Highlights •Net sales of $633.7 million •Reported net income attributable to Century stockholders of $1.8 million, or $0.02 per diluted share; Adjusted net i

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 2, 2026 Century Aluminum

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 2, 2026 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission F

AGREEMENT OF PURCHASE AND SALE Century Aluminum Facility, Hawesville, KY By and Between CENTURY ALUMINUM OF KENTUCKY GENERAL PARTNERSHIP, a Kentucky general partnership, Seller Justified datapower LLC, a Delaware limited liability company, Purchaser

Exhibit 10.1 Execution Version AGREEMENT OF PURCHASE AND SALE Century Aluminum Facility, Hawesville, KY By and Between CENTURY ALUMINUM OF KENTUCKY GENERAL PARTNERSHIP, a Kentucky general partnership, Seller and Justified datapower LLC, a Delaware limited liability company, Purchaser TABLE OF CONTENTS 1. Definitions 1 2. Sale; Purchase Price 5 (1) Purchase 5 (2) Purchase Price 5 (3) Closing Paymen

NEW DIGITAL INFRASTRUCTURE CAMPUS TO BE BUILT AT HAWESVILLE

Exhibit 99.1 NEW DIGITAL INFRASTRUCTURE CAMPUS TO BE BUILT AT HAWESVILLE CHICAGO, Feb. 2, 2026 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced the sale of the Hawesville, Kentucky site, which will be redeveloped by TeraWulf Inc. (NASDAQ:WULF) into a digital infrastructure campus supporting high-performance computing and artificial intelligence workloads. Century will ret

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 6, 2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 6, 2025 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorpor

$MM (except shipments and per share data) Q3 2025 Q2 2025 Aluminum shipments (tonnes) 162,442 175,741 Net sales $ 632.2 $ 628.1 Net income (loss) attributable to Century stockholders $ 14.9 $ (4.6) Diluted earnings (loss) per share attributable to Ce

Exhibit 99.1 Century Aluminum Company Reports Third Quarter 2025 Results Chicago, November 6, 2025 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its third quarter 2025 results. Third Quarter 2025 Financial Results $MM (except shipments and per share data) Q3 2025 Q2 2025 Aluminum shipments (tonnes) 162,442 175,741 Net sales $ 632.2 $ 628.1 Net income (loss) attributabl

$MM (except shipments and per share data) Q3 2025 Q2 2025 Aluminum shipments (tonnes) 162,442 175,741 Net sales $ 632.2 $ 628.1 Net income (loss) attributable to Century stockholders $ 14.9 $ (4.6) Diluted earnings (loss) per share attributable to Ce

Exhibit 99.1 Century Aluminum Company Reports Third Quarter 2025 Results Chicago, November 6, 2025 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its third quarter 2025 results. Third Quarter 2025 Financial Results $MM (except shipments and per share data) Q3 2025 Q2 2025 Aluminum shipments (tonnes) 162,442 175,741 Net sales $ 632.2 $ 628.1 Net income (loss) attributabl

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 6, 2025 Century Aluminum

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 6, 2025 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2025 ☐ TRANSITION REPORT PURSUANT

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-344

Century Aluminum Reports Electrical Equipment Failure Affecting One Potline at Grundartangi, Iceland Smelter

Exhibit 99.1 Century Aluminum Reports Electrical Equipment Failure Affecting One Potline at Grundartangi, Iceland Smelter CHICAGO, October 21, 2025 (GLOBE NEWSWIRE) - Norðurál Grundartangi ehf, a wholly-owned subsidiary of Century Aluminum Company (NASDAQ:CENX), announced today that it was forced to temporarily stop production on one of its two potlines due to an electrical equipment failure at th

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): October 21, 2025 Century Aluminum

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): October 21, 2025 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission F

XBRL INSTANCE DOCUMENT

iso4217:USD 0000949157 2024-01-01 2024-12-31 0000949157 country:JM cenx:CenturyAluminumCompanyMember cenx:GovernmentOfJamaicaMember 2024-01-01 2024-12-31 0000949157 cenx:CenturyAluminumCompanyMember cenx:NotApplicableMember 2024-01-01 2024-12-31 0000949157 cenx:CenturyAluminumCompanyMember 2024-01-01 2024-12-31 0000949157 cenx:CenturyAluminumCompanyMember 1 2024-01-01 2024-12-31 0000949157 cenx:CenturyAluminumCompanyMember 2 2024-01-01 2024-12-31 0000949157 cenx:CenturyAluminumCompanyMember 3 2024-01-01 2024-12-31 0000949157 cenx:CenturyAluminumCompanyMember 4 2024-01-01 2024-12-31 0000949157 cenx:CenturyAluminumCompanyMember 5 2024-01-01 2024-12-31 2.

XBRL TAXONOMY EXTENSION SCHEMA DOCUMENT

Government of Jamaica [Member] JAMAICA Not applicable [Member] Century Aluminum Company [Member] Bauxite [Member] Aluminum [Member]

144

144 0002049924 XXXXXXXX LIVE 0000949157 CENTURY ALUMINUM CO 001-34474 1 SOUTH WACKER DRIVE SUITE 1000 CHICAGO IL 60606 3126963101 Hafberg Agust F Officer Common Stock Charles Schwab & Co 3000 Schwab Way Westlake TX 76262 9493 249950.69 93339121 09/25/2025 NASDAQ GS Common Stock 12/31/2024 Restricted Stock Grant Issuer N 9493 12/31/2024 Services Rendered Y 09/25/2025 Agust F Hafberg

Century Aluminum Company Resource Extraction Payment Report for the fiscal year ended December 31, 2024 Currency of Report: United States Dollar (USD)

Exhibit 2.01 Century Aluminum Company Resource Extraction Payment Report for the fiscal year ended December 31, 2024 Currency of Report: United States Dollar (USD) Government-level disclosure The table below sets forth our payments made to the Government of Jamaica for the fiscal year ended December 31, 2024, by type of payment. The Government of Jamaica is the only government that received paymen

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM SD SPECIALIZED DISCLOSURE REPORT Century Aluminum Company (Exact name of the registrant as specified in its charter) Delaware 001-34474 13-3070826 (State or other jurisdicti

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM SD SPECIALIZED DISCLOSURE REPORT Century Aluminum Company (Exact name of the registrant as specified in its charter) Delaware 001-34474 13-3070826 (State or other jurisdiction of incorporation or organization) (Commission File Number) (IRS Employer Identification No.) One South Wacker Drive 60606 Suite 1000 (Zip Code) Chi

144

144 0002014963 XXXXXXXX LIVE 0000949157 CENTURY ALUMINUM CO 001-34474 1 SOUTH WACKER DRIVE SUITE 1000 CHICAGO IL 60606 3126963101 Calloway Kenneth L Officer Common Stock Charles Schwab & Co 3000 Schwab Way Westlake TX 76262 16450 433457.

Form of RSU Award Agreement (Directors) under the 2025 Incentive Plan

CENTURY ALUMINUM COMPANY INDEPENDENT NON-EMPLOYEE DIRECTOR ANNUAL RESTRICTED STOCK UNIT AWARD AGREEMENT UNDER THE CENTURY ALUMINUM COMPANY 2025 INCENTIVE PLAN This Annual Restricted Stock Unit Award Agreement (this “Agreement”) is made as of [], 2025 (the “Award Date”), by and between Century Aluminum Company (the “Company”) and [] (“Participant”).

Form of PSU Award Agreement under the 2025 Incentive Plan

CENTURY ALUMINUM COMPANY PERFORMANCE STOCK UNIT AWARD AGREEMENT UNDER THE CENTURY ALUMINUM COMPANY 2025 INCENTIVE PLAN This Performance Stock Unit Award Agreement (this “Agreement”) is made as of [] (the “Award Date”), between Century Aluminum Company (the “Company”) and [] (“Participant”).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 ☐ TRANSITION REPORT PURSUANT TO S

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-34474 Ce

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 7, 2025 Century Aluminum C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 7, 2025 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission Fil

Form of RSU Award Agreement under the 2025 Incentive Plan

CENTURY ALUMINUM COMPANY RESTRICTED STOCK UNIT AWARD AGREEMENT UNDER THE CENTURY ALUMINUM COMPANY 2025 INCENTIVE PLAN This Restricted Stock Unit Award Agreement (this “Agreement”) is made as of [], (the “Award Date”), between Century Aluminum Company (the “Company”) and [] (“Participant”).

$MM (except shipments and per share data) Q2 2025 Q1 2025 Aluminum shipments (tonnes) 175,741 168,672 Net sales $ 628.1 $ 633.9 Net (loss) income attributable to Century stockholders $ (4.6) $ 29.7 Diluted (loss) earnings per share attributable to Ce

Exhibit 99.1 Century Aluminum Company Reports Second Quarter 2025 Results Chicago, August 7, 2025 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its second quarter 2025 results. Second Quarter 2025 Financial Results $MM (except shipments and per share data) Q2 2025 Q1 2025 Aluminum shipments (tonnes) 175,741 168,672 Net sales $ 628.1 $ 633.9 Net (loss) income attributab

Indenture, dated as of July 22, 2025, between Century Aluminum Company, the Guarantors (as defined therein) and Wilmington Trust, National Association, as trustee and noteholder collateral agent.

  Exhibit 4.1 CENTURY ALUMINUM COMPANY, as Issuer   the GUARANTORS party hereto   and   WILMINGTON TRUST, National Association, as Trustee and Noteholder Collateral Agent       Indenture   Dated as of July 22, 2025       6.875% Senior Secured Notes due 2032       CROSS-REFERENCE TABLE   TIA Sections Indenture Sections 310(a)(1) 7.10 (a)(2) 7.10 (a)(3) Not Applicable (a)(4) Not Applicable (a)(5) 7.

Second Lien Pledge and Security Agreement, dated as of July 22, 2025 by and among Century Aluminum Company, the other Grantors (as defined therein) and Wilmington Trust, National Association, as collateral agent.

Exhibit 10.1 SECOND LIEN PLEDGE AND SECURITY AGREEMENT dated as of July 22, 2025 among CENTURY ALUMINUM COMPANY, the other Grantors party hereto and WILMINGTON TRUST, NATIONAL ASSOCIATION, as Collateral Agent NOTWITHSTANDING ANYTHING HEREIN TO THE CONTRARY, THE LIENS AND SECURITY INTERESTS GRANTED TO THE COLLATERAL AGENT PURSUANT TO THIS AGREEMENT AND THE EXERCISE OF ANY RIGHT OR REMEDY BY THE COL

Century Aluminum Company Closes Private Offering of $400 Million of Senior Secured Notes

Exhibit 99.1 Century Aluminum Company Closes Private Offering of $400 Million of Senior Secured Notes 07/22/25 CHICAGO, July 22, 2025 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) (“Century”) announced today that it closed its private offering of 6.875% senior secured notes due August 2032 (the “Secured Notes”) for gross proceeds of $400 million. The net proceeds from the offering wer

Amendment No. 5, dated as of July 22, 2025, to the Second Amended and Restated Loan and Security Agreement, dated as of May 16, 2018, among Century Aluminum Company, Century Aluminum of South Carolina, Inc., Century Aluminum of Kentucky General Partnership, NSA General Partnership and Century Aluminum Sebree LLC, as borrowers, and Wells Fargo Capital Finance, LLC, as agent and lender.

Exhibit 10.3 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED LOAN AND SECURITY AGREEMENT THIS AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED LOAN AND SECURITY AGREEMENT (this "Amendment") is entered into as of July 22, 2025, by and among the Lenders party hereto, WELLS FARGO CAPITAL FINANCE, LLC, a Delaware limited liability company, as the agent for the Lenders (in such capacity, "Agent"), Century

Collateral Agency Agreement, dated as of July 22, 2025, by and among Century Aluminum Company, the other Grantors (as defined therein) and Wilmington Trust, National Association, as trustee and collateral agent.

  Exhibit 10.2   COLLATERAL AGENCY AGREEMENT   Dated as of July 22, 2025   among   CENTURY ALUMINUM COMPANY,   THE OTHER GRANTORS PARTY HERETO,   WILMINGTON TRUST, NATIONAL ASSOCIATION, as trustee under the Senior Secured Note Indenture,   and   WILMINGTON TRUST, NATIONAL ASSOCIATION, as Collateral Agent       TABLE OF CONTENTS       Page       SECTION 1.      Definitions      3 SECTION 2.      Th

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): July 22, 2025 Century Aluminum Co

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): July 22, 2025 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): July 16, 2025 Century Aluminum Co

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): July 16, 2025 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File

Century Aluminum Company Announces Pricing of Private Offering of $400 million of Senior Secured Notes

Exhibit 99.2 Century Aluminum Company Announces Pricing of Private Offering of $400 million of Senior Secured Notes 07/16/25 CHICAGO, July 16, 2025 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) (“Century”) announced today that it had priced its previously announced private offering (the “Secured Notes Offering”) of $400 million aggregate principal amount of 6.875% senior secured notes

Century Aluminum Company Announces Proposed Private Offering of $400 Million of Senior Secured Notes

Exhibit 99.1 Century Aluminum Company Announces Proposed Private Offering of $400 Million of Senior Secured Notes 07/16/25 CHICAGO, July 16, 2025 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) (“Century”) announced today a proposed private offering of $400 million aggregate principal amount of senior secured notes due July 2032 (the “Secured Notes”) subject to market and other conditio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 16, 2025 Century Aluminum Co

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 16, 2025 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File

Power of Attorney.*

EXHIBIT 24 POWER OF ATTORNEY The undersigned, acting in the capacity or capacities stated with their respective names below, hereby constitute and appoint Jesse E.

Century Aluminum Company 2025 Incentive Plan*

EXHIBIT 99.1 CENTURY ALUMINUM COMPANY 2025 INCENTIVE PLAN Article 1 Establishment, Purpose, and Duration 1.1            Establishment. Century Aluminum Company, a Delaware corporation, establishes this incentive compensation plan known as the Century Aluminum Company 2025 Incentive Plan (this “Plan”). This Plan permits the grant of Nonqualified Stock Options, Incentive Stock Options, Stock Appreci

As filed with the Securities and Exchange Commission on June 16, 2025

As filed with the Securities and Exchange Commission on June 16, 2025 Registration No.

Filing Fee Table.

Calculation of Filing Fee Tables S-8 CENTURY ALUMINUM CO Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee 1 Equity Common Stock Other 5,519,839 $ 19.

SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Definitive Proxy Statement x Definitive Additional Materials o Soliciting Material Pursuant to § 240.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 ☐ TRANSITION REPORT PURSUANT TO

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-34474 C

$MM (except shipments and per share data) Q1 2025 Q4 2024 Aluminum shipments (tonnes) 168,672 166,677 Net sales $ 633.9 $ 630.9 Net income attributable to Century stockholders $ 29.7 $ 45.2 Diluted earnings per share attributable to Century stockhold

Exhibit 99.1 Century Aluminum Company Reports First Quarter 2025 Results Chicago, May 7, 2025 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its first quarter 2025 results. First Quarter 2025 Financial Results $MM (except shipments and per share data) Q1 2025 Q4 2024 Aluminum shipments (tonnes) 168,672 166,677 Net sales $ 633.9 $ 630.9 Net income attributable to Century

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 7, 2025 Century Aluminum Comp

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 7, 2025 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File N

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) ☒ Filed by the Registrant ☐ Filed by a Party other than the Registr

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) ☒ Filed by the Registrant ☐ Filed by a Party other than the Registrant Check the appropriate box: ☐ Preliminary Proxy Statement ☐ CONFIDENTIAL, FOR USE OF THE COMMISSION ONLY (AS PERMITTED BY RULE 14a-6(e)(2)) ☒ Defin

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) ☒ Filed by the Registrant ☐ Filed by a Party other than the Registrant Check the appropriate box: ☐ Preliminary Proxy Statement ☐ CONFIDENTIAL, FOR USE OF THE COMMISSION ONLY (AS PERMITTED BY RULE 14a-6(e)(2)) ☒ Defin

Century Aluminum Names Veteran Executive Peter Trpkovski Chief Financial Officer

Exhibit 99.1 Century Aluminum Names Veteran Executive Peter Trpkovski Chief Financial Officer CHICAGO, March 21, 2025 - Century Aluminum Company (NASDAQ:CENX) announced today that its Board of Directors has appointed Peter Trpkovski to be the Company’s next Executive Vice President and Chief Financial Officer. As CFO, Trpkovski will build on his 12-years of experience at Century and focus on advan

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 21, 2025 Century Aluminum C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 21, 2025 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission Fil

Incentive Compensation Recoupment Policy

Exhibit 97.1 CENTURY ALUMINUM COMPANY INCENTIVE COMPENSATION RECOUPMENT POLICY A.INTRODUCTION This policy has been adopted by the Board of Directors (the “Board”) of Century Aluminum Company (the “Company”) to provide for the recovery of (i) any erroneously awarded incentive-based compensation from executive officers of the Company in the event of an accounting restatement as required by Rule 10D-

List of Subsidiaries

EXHIBIT 21.1 CENTURY ALUMINUM COMPANY Subsidiaries of the Registrant Company Name State or Other Jurisdiction of Incorporation or Organization Name Under Business is Conducted Century Aluminum of South Carolina, Inc. Delaware Century Aluminum of South Carolina, Inc. Century Aluminum Sebree, LLC Delaware Century Aluminum Sebree, LLC Century Marketer LLC Delaware Century Marketer LLC Century Califor

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE FISCAL YEAR ENDED DECEMBER 31, 2024 ☐ TRANSITION REPORT PURSUANT TO SECTI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE FISCAL YEAR ENDED DECEMBER 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number 001-34474 CENTURY ALUMINUM COMPANY (Exact name of registrant as specif

Powers of Attorney

EXHIBIT 24.1 POWER OF ATTORNEY I hereby constitute and appoint John DeZee and Paul Sharobeem as my true and lawful attorney-in-fact and agent, with full power of substitution, for me and in my name, in any and all capacities, to sign on my behalf the Annual Report on Form 10-K of Century Aluminum Company for the fiscal year ended December 31, 2024, and any amendment or supplement thereto; and to f

rading Policy

EXHIBIT 19.1 Insider Trading Policy March 12, 2024 Background Century Aluminum Company (together with its subsidiaries, the “Company”) has adopted this Insider Trading Policy with respect to the trading of the Company’s securities and the securities of other publicly traded companies with whom the Company may exchange information as part of our business. Securities laws in the U.S. and many other

Technical Report Summary for Jamalco

SK 1300 Technical Report Summary – Jamalco Bauxite Operations Special Mining Leases 130 and 169 Jamaica Prepared for Century Aluminum Company by ALUMINPRO Aluminium Industry Professionals Inc.

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 20, 2025 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission

$MM (except shipments and per share data) Q4 2024 Q3 2024 FY 2024 FY 2023 Shipments (tonnes) 166,677 168,755 677,967 700,680 Net sales $ 631.0 $ 539.1 $ 2,220.3 $ 2,185.4 Net income (loss) attributable to Century stockholders $ 47.7 $ 47.3 $ 339.4 $

Exhibit 99.1 Century Aluminum Company Reports Fourth Quarter 2024 Results Chicago, February 20, 2025 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its fourth quarter and full year 2024 results. Fourth Quarter 2024 Highlights •Net sales $631.0 million •Reported net income attributable to Century stockholders of $47.7 million, or $0.47 per diluted share; adjusted net inc

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 5, 2024 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission F

Amendment Agreement - Vlissingen Credit Facility

Amendment agreement Dated October 1, 2024 for CENTURY ALUMINUM VLISSINGEN B.V. as Company with GLENCORE INTERNATIONAL AG acting as Lender RELATING TO A FACILITY AGREEMENT DATED 9 December 2022 Ref: L-330238 CONTENTS CLAUSE PAGE 1. Definitions and interpretation 2. Conditions precedent 3. Representations 4. Amendment 5. Transaction expenses 6. Miscellaneous 7. Governing law THE SCHEDULES SCHEDULE P

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2024 ☐ TRANSITION REPORT PURSUANT

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-344

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 4, 2024 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission F

$MM (except shipments and per share data) Q3 2024 Q2 2024 Aluminum shipments (tonnes) 168,755 167,908 Net sales $ 539.1 $ 560.8 Net income (loss) attributable to Century stockholders $ 47.3 $ (2.5) Diluted earnings (loss) per share attributable to Ce

Exhibit 99.1 Century Aluminum Company Reports Third Quarter 2024 Results Chicago, November 4, 2024 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its third quarter 2024 results. Business Highlights •Net sales of $539.1 million •Realized LME aluminum price of $2,451/MT in third quarter is up $163/MT from prior quarter •Reported net income attributable to Century stockhol

XBRL SCHEMA FILE

XBRL INSTANCE FILE

0000949157 2023-01-01 2023-12-31 iso4217:USD 2.01 SD false 0000949157 Century Aluminum Company 2023-12-31 USD 0

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM SD SPECIALIZED DISCLOSURE REPORT Century Aluminum Company (Exact name of registrant as specified in its charter) Delaware 001-34474 13-3070826 (State or other jurisdiction of incorporation) (Commission File Number) (I.R.S. Employer Identification No.) One South Wacker Drive Suite 1000 Chicago Illinois 60606 (Address of pr

Resource Extraction Payment Report as required by Item 2.01 of this Form.

Exhibit 99.1 Resource Extraction Payment Report As disclosed under Item 2.01, on May 2, 2023, the registrant’s wholly-owned subsidiary, Century Aluminum Jamaica Holdings, Inc., completed the acquisition of all the outstanding share capital of General Alumina Holdings Limited, the holder of a 55% interest in Jamalco JV (“Jamalco”), an unincorporated joint venture engaged in bauxite mining and alumi

CENX / Century Aluminum Company / GLENCORE INTERNATIONAL AG - SC 13D/A Activist Investment

Page 1 of 13 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 28)* CENTURY ALUMINUM COMPANY Name of Issuer COMMON STOCK, $0.01 Par Value (Title of Class of Securities) 156431 10 8 (CUSIP Number) Steven Kalmin Glencore International AG Baarermattstrasse 3 CH-6340 Baar Switzerland +41 41 709 2000 With copi

JOINT FILING AGREEMENT

EXHIBIT 1 JOINT FILING AGREEMENT Each of the undersigned hereby agrees that this Amendment No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 ☐ TRANSITION REPORT PURSUANT TO S

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-34474 Ce

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 8, 2024 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission Fil

$MM (except shipments and per share data) Q2 2024 Q1 2024 Aluminum shipments (tonnes) 167,908 174,627 Net sales $ 560.8 $ 489.5 Net (loss) income attributable to Century stockholders $ (2.5) $ 246.8 Diluted (loss) earnings per share attributable to C

Exhibit 99.1 Century Aluminum Company Reports Second Quarter 2024 Results Chicago, August 8, 2024 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its second quarter 2024 results. Business Highlights •Net sales of $560.8 million •Realized LME aluminum price of $2,288/MT in second quarter is up $98/MT from prior quarter •Reported net loss attributable to Century stockholde

CENX / Century Aluminum Company / STATE STREET CORP Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 EXIT FILING CENTURY ALUMINUM CO (NAME OF ISSUER) COMMON STOCK (TITLE OF CLASS OF SECURITIES) 156431108 (CUSIP NUMBER) 06/30/2024 (DATE OF EVENT WHICH REQUIRES FILING OF THIS STATEMENT) CHECK THE APPROPRIATE BOX TO DESIGNATE THE RULE PURSUANT TO WHICH THIS SCHEDULE IS FILED

Financial Statements and Exhibits, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 3, 2024 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File

SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant x Filed by a Party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Definitive Proxy Statement x Definitive Additional Materials ¨ Soliciting Material Pursuant to § 240.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 ☐ TRANSITION REPORT PURSUANT TO

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-34474 C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 1, 2024 Century Aluminum Comp

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 1, 2024 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File N

$MM (except shipments and per share data) Q1 2024 Q4 2023 Aluminum shipments (tonnes) 174,627 173,871 Net sales $ 489.5 $ 512.3 Net income attributable to Century stockholders $ 246.8 $ 30.0 Diluted earnings per share attributable to Century stockhol

Exhibit 99.1 Century Aluminum Company Reports First Quarter 2024 Results Chicago, May 1, 2024 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its first quarter 2024 results. Business Highlights •Net sales of $489.5 million •Realized LME aluminum price of $2,190/T in first quarter is up $8/T from prior quarter •Reported net income attributable to Century stockholders of $

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Ame

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confide

COURTESY COPY

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confide

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Ame

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confide

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 25, 2024 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission Fil

Century Aluminum Selected by U.S. Department of Energy to Receive $500 Million Investment to Build New Green Aluminum Smelter to Accelerate Industrial Decarbonization

Century Aluminum Selected by U.S. Department of Energy to Receive $500 Million Investment to Build New Green Aluminum Smelter to Accelerate Industrial Decarbonization Chicago, March 25, 2024 (GLOBE NEWSWIRE) – Today, Century Aluminum Company (NASDAQ: CENX) (“Century”) was selected by the U.S. Department of Energy (“DOE”) Office of Clean Energy Demonstrations to begin award negotiations for up to $

List of Subsidiaries

EXHIBIT 21.1 CENTURY ALUMINUM COMPANY Subsidiaries of the Registrant Company Name State or Other Jurisdiction of Incorporation or Organization Name Under Business is Conducted Century Aluminum of South Carolina, Inc. Delaware Century Aluminum of South Carolina, Inc. Century Aluminum Sebree, LLC Delaware Century Aluminum Sebree, LLC Century Marketer LLC Delaware Century Marketer LLC Century Califor

Amendment to Revolving Credit Facility, dated December 7, 2023, between Nordural Grundartangi ehf, as borrower and Landsbankinn hf

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE FISCAL YEAR ENDED DECEMBER 31, 2023 ☐ TRANSITION REPORT PURSUANT TO SECTI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE FISCAL YEAR ENDED DECEMBER 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number 001-34474 CENTURY ALUMINUM COMPANY (Exact name of registrant as specif

Powers of Attorney

EXHIBIT 24.1 POWER OF ATTORNEY I hereby constitute and appoint John DeZee and Paul Sharobeem as my true and lawful attorney-in-fact and agent, with full power of substitution, for me and in my name, in any and all capacities, to sign on my behalf the Annual Report on Form 10-K of Century Aluminum Company for the fiscal year ended December 31, 2023, and any amendment or supplement thereto; and to f

Incentive Compensation Recoupment Policy

1 CENTURY ALUMINUM COMPANY INCENTIVE COMPENSATION RECOUPMENT POLICY A. INTRODUCTION This policy has been adopted by the Board of Directors (the “Board”) of Century Aluminum Company (the “Company”) to provide for the recovery of (i) any erroneously awarded incentive-based compensation from executive officers of the Company in the event of an accounting restatement as required by Rule 10D-1 (“Rule 1

$MM (except shipments and per share data) Q4 2023 Q3 2023 FY 2023 FY 2022 Shipments (tonnes) 173,871 171,995 700,680 768,691 Net sales $ 512.3 $ 545.2 $ 2,185.4 $ 2,777.3 Net income (loss) attributable to Century stockholders $ 30.0 $ (42.0) $ (43.1)

Exhibit 99.1 Century Aluminum Company Reports Fourth Quarter 2023 Results Chicago, February 21, 2024 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its fourth quarter and full year 2023 results. Fourth Quarter 2023 Highlights •Net sales $512.3 million •Reported net income attributable to Century stockholders of $30.0 million, or $0.30 per diluted share; adjusted net inc

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 21, 2024 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission

CENX / Century Aluminum Company / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SC 13G/A 1 tv0035-centuryaluminumco.htm SCHEDULE 13G/A SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 4)* Name of issuer: Century Aluminum Co Title of Class of Securities: Common Stock CUSIP Number: 156431108 Date of Event Which Requires Filing of this Statement: December 29, 2023 Check the appropriate box to designa

CENX / Century Aluminum Company / STATE STREET CORP Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 AMENDED FILING CENTURY ALUMINUM CO (NAME OF ISSUER) COMMON STOCK (TITLE OF CLASS OF SECURITIES) 156431108 (CUSIP NUMBER) 12/31/2023 (DATE OF EVENT WHICH REQUIRES FILING OF THIS STATEMENT) CHECK THE APPROPRIATE BOX TO DESIGNATE THE RULE PURSUANT TO WHICH THIS SCHEDULE IS FI

CENX / Century Aluminum Company / BlackRock Inc. Passive Investment

SC 13G/A 1 us1564311082012324.txt us1564311082012324.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: 3) CENTURY ALUMINUM CO - (Name of Issuer) Common Stock - (Title of Class of Securities) 156431108 - (CUSIP Number) December 31, 2023 - (Date of Event Which Requires Filing of this Statement) Check the appropriate bo

FORM OF IRREVOCABLE PROXY TO VOTE STOCK OF CENTURY ALUMINUM COMPANY March 24, 2023

Exhibit 6 FORM OF IRREVOCABLE PROXY TO VOTE STOCK OF CENTURY ALUMINUM COMPANY March 24, 2023 Each of the undersigned, currently a direct or indirect stockholder (each, a “Stockholder”) of Century Aluminum Company, a Delaware corporation (the “Company”), hereby irrevocably appoints the Chief Accounting Officer of the Company and the Treasurer of the Company, for so long as they remain in their resp

CENX / Century Aluminum Company / GLENCORE INTERNATIONAL AG - SC 13D/A Activist Investment

Page 1 of 13 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 27)* CENTURY ALUMINUM COMPANY Name of Issuer COMMON STOCK, $0.01 Par Value (Title of Class of Securities) 156431 10 8 (CUSIP Number) Steven Kalmin Glencore International AG Baarermattstrasse 3 CH-6340 Baar Switzerland +41 41 709 2000 With copi

1 December 2023 [CHARGOR] (as Chargor) HSBC BANK PLC (as Chargee) SECURITY DEED 99 Bishopsgate London EC2M 3XF United Kingdom Tel: +44.20.7710.1000

Exhibit 7 1 December 2023 [CHARGOR] (as Chargor) and HSBC BANK PLC (as Chargee) SECURITY DEED 99 Bishopsgate London EC2M 3XF United Kingdom Tel: +44.

JOINT FILING AGREEMENT

EX-99.1 2 tm241621d1ex1.htm EXHIBIT 1 EXHIBIT 1 JOINT FILING AGREEMENT Each of the undersigned hereby agrees that this Amendment No. 27 to the statement on Schedule 13D is being filed with the Securities and Exchange Commission on behalf of each of the undersigned pursuant to Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended. Date: January 5, 2024 Glencore AG By: /s/ Stephan Hube

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 19, 2023 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission

Inflation Reduction Act – Section 45X December 19, 2023 1 Certain statements in this presentation, and those made by Century Aluminum Company management on the conference call, relate to future events and expectations and are "forward-looking stateme

Inflation Reduction Act – Section 45X December 19, 2023 1 Certain statements in this presentation, and those made by Century Aluminum Company management on the conference call, relate to future events and expectations and are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 ☐ TRANSITION REPORT PURSUANT

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-344

$MM (except shipments and per share data) Q2 2023 Q3 2023 Aluminum shipments (tonnes) 173,649 171,995 Net sales $ 575.5 $ 545.2 Net income (loss) attributable to Century stockholders $ 7.5 $ (42.0) Diluted income (loss) per share attributable to Cent

Exhibit 99.1 Century Aluminum Company Reports Third Quarter 2023 Results Chicago, November 8, 2023 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its third quarter 2023 results. Business Highlights •Net sales $545.2 million •Realized LME aluminum price of $2,237/T in third quarter is down $134/T from prior quarter •Falling energy and other raw material costs •Completed

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 8, 2023 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission F

Supplemental Indenture, dated June 12, 2023, for Century Aluminum Company's 7.5% Senior Secured Notes due 2028, by and among Century Aluminum Company, as issuer and Wilmington Trust, National Association, as trustee

a20230630q2ex102 1 SUPPLEMENTAL INDENTURE dated as of June 12, 2023 among CENTURY ALUMINUM COMPANY, The Guarantor(s) Party Hereto and WILMINGTON TRUST, NATIONAL ASSOCIATION, as Trustee 7.

$MM (except shipments and per share data) Q1 2023 Q2 2023 Aluminum shipments (tonnes) 181,165 173,649 Net sales $ 552.4 $ 575.5 Net (loss) income attributable to Century stockholders $ (38.6) $ 7.5 Diluted (loss) income per share attributable to Cent

Exhibit 99.1 Century Aluminum Company Reports Second Quarter 2023 Results Chicago, August 9, 2023 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its second quarter 2023 results. Business Highlights •Net sales $575.5 million •Realized LME aluminum price of $2,371/T in second quarter is up $21/T from prior quarter •Decreased input costs mainly from reduced pricing across

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 ☐ TRANSITION REPORT PURSUANT TO S

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-34474 Ce

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 9, 2023 Century Aluminum C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 9, 2023 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission Fil

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 5, 2023 Century Aluminum Com

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 5, 2023 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File

Century Aluminum Company Announces the Expansion of its Board of Directors and Additional Management Changes

Century Aluminum Company Announces the Expansion of its Board of Directors and Additional Management Changes Tamla Olivier Joins the Board as a New Director; Shelly Harrison to Retire; Peter Trpkovski Named Senior Vice President, Finance and Treasurer CHICAGO, June 9, 2023 (GLOBE NEWSWIRE) – Century Aluminum Company (NASDAQ: CENX) today announced that on Monday, June 5, 2023, the Company’s stockholders voted to increase the size of Century’s Board of Directors (the “Board”) from six to seven members, and elected Tamla Olivier to join Century’s six incumbent Directors, as an independent director with a term expiring at the Company’s annual meeting of stockholders in 2024.

Century Aluminum Company One South Wacker Drive Suite 1000 Chicago, IL 60606

Century Aluminum Company One South Wacker Drive Suite 1000 Chicago, IL 60606 VIA EDGAR June 8, 2023 Division of Corporation Finance Securities and Exchange Commission 100 F Street, N.

Century Aluminum Company One South Wacker Drive Suite 1000 Chicago, IL 60606

Century Aluminum Company One South Wacker Drive Suite 1000 Chicago, IL 60606 VIA EDGAR May 15, 2023 Division of Corporation Finance Securities and Exchange Commission 100 F Street, N.

As filed with the Securities and Exchange Commission on May 12, 2023

As filed with the Securities and Exchange Commission on May 12, 2023 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 ☐ TRANSITION REPORT PURSUANT TO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-34474 Century Aluminum Co

$MM (except shipments and per share data) Q4 2022 Q1 2023 Shipments (tonnes) 169,471 181,165 Net sales $ 529.9 $ 552.4 Net loss $ (113.5) $ (38.6) Diluted loss per share $ (1.24) $ (0.42) Adjusted net loss(1) $ (31.3) $ (11.3) Adjusted loss per share

Exhibit 99.1 Century Aluminum Company Reports First Quarter 2023 Results Chicago, May 8, 2023 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its first quarter 2023 results. Business Highlights •Realized LME aluminum price of $2,350/T in first quarter is up $42/T from prior quarter •Kentucky energy costs down $30/MWh, 47% improvement from Q4 •Strong total liquidity of $2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 8, 2023 Century Aluminum Comp

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 8, 2023 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File N

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 2, 2023 Century Aluminum Comp

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 2, 2023 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File N

Share Sale and Purchase Agreement, dated as of May 2, 2023, by and among Century Aluminum Jamaica Holdings, Inc., Noble New Asset Intermediate Co Limited, Noble Group Holdings Limited and Noble Resources International Pte, Ltd

Exhibit 10.1 Execution Version Strictly Confidential Dated 2 May, 2023 Share Sale and Purchase Agreement in relation to General Alumina Holdings Limited among Noble New Asset Intermediate Co Limited as Seller Noble Group Holdings Limited as Seller Parent Noble Resources International Pte. Ltd. as NRIPL and Century Aluminum Jamaica Holdings, Inc. as Purchaser Table of Contents Page 1. Interpretatio

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UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Ame

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confide

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Ame

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confide

LETTER

United States securities and exchange commission logo March 23, 2023 Paul Sharobeem Associate General Counsel CENTURY ALUMINUM CO One South Wacker Drive, Suite 1000 Chicago, Illinois 60606 Re: CENTURY ALUMINUM CO Registration Statement on Form S-3 Filed March 17, 2023 File No.

As filed with the Securities and Exchange Commission on March 17, 2023

As filed with the Securities and Exchange Commission on March 17, 2023 Registration No.

Fee Table.

Exhibit 107 Calculation of Filing Fee Table Form S-3 (Form Type) Century Aluminum Company (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities and Carry Forward Securities Security Type Security Class Title(1) Fee Calculation Rule or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount

Powers of Attorney

Exhibit 24.1 POWER OF ATTORNEY KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below, acting in the capacity or capacities stated with their respective names below, hereby constitutes and appoints John DeZee and Paul Sharobeem, and each of them individually, as his or her true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, fo

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE FISCAL YEAR ENDED DECEMBER 31, 2022 ☐ TRANSITION REPORT PURSUANT TO SECTI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE FISCAL YEAR ENDED DECEMBER 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number 001-34474 CENTURY ALUMINUM COMPANY (Exact name of registrant as specif

Powers of Attorney

EXHIBIT 24.1 POWER OF ATTORNEY I hereby constitute and appoint John DeZee and Paul Sharobeem as my true and lawful attorney-in-fact and agent, with full power of substitution, for me and in my name, in any and all capacities, to sign on my behalf the Annual Report on Form 10-K of Century Aluminum Company for the fiscal year ended December 31, 2022, and any amendment or supplement thereto; and to f

List of Subsidiaries

EXHIBIT 21.1 CENTURY ALUMINUM COMPANY Subsidiaries of the Registrant Company Name State or Other Jurisdiction of Incorporation or Organization Name Under Business is Conducted Century Aluminum of South Carolina, Inc. Delaware Century Aluminum of South Carolina, Inc. Century Aluminum Sebree, LLC Delaware Century Aluminum Sebree, LLC Century Marketer LLC Delaware Century Marketer LLC Century Califor

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 23, 2023 Century Aluminu

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 23, 2023 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission

$MM (except shipments and per share data) Q3 2022 Q4 2022 FY 2021 FY 2022 Shipments (tonnes) 173,725 169,471 783,647 768,691 Net sales $ 637.2 $ 529.9 $ 2,212.5 $ 2,777.3 Net income (loss) $ 44.3 $ (113.5) $ (167.1) $ (14.1) Diluted earnings (loss) p

Exhibit 99.1 Century Aluminum Company Reports Fourth Quarter 2022 Results Chicago, February 23, 2023 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its fourth quarter and full year 2022 results. Fourth Quarter 2022 Highlights •Net sales $529.9 million •Cost savings programs partially offset high power prices and other raw material cost pressure •Reported net loss of $(1

Fee Table.

Exhibit 107 Calculation of Filing Fee Table Form S-3 (Form Type) Century Aluminum Company (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities and Carry Forward Securities Security Type Security Class Title(1) Fee Calculation Rule or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount

As filed with the Securities and Exchange Commission on February 14, 2023

POSASR 1 tm236592d1s3asr.htm POSASR As filed with the Securities and Exchange Commission on February 14, 2023 Registration No. 333-265125 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 POST EFFECTIVE AMENDMENT NO. 1 TO FORM S-3 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 CENTURY ALUMINUM COMPANY* (Exact name of Registrant as specified in its charter) Delaware (

CENX / Century Aluminum Co / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SC 13G/A 1 tv0035-centuryaluminumco.htm SCHEDULE 13G/A SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 3)* Name of issuer: Century Aluminum Co. Title of Class of Securities: Common Stock CUSIP Number: 156431108 Date of Event Which Requires Filing of this Statement: December 30, 2022 Check the appropriate box to design

CENX / Century Aluminum Co / STATE STREET CORP Passive Investment

SC 13G/A 1 CenturyAluminumCo.txt UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 AMEMDED FILING CENTURY ALUMINUM CO (NAME OF ISSUER) COMMON STOCK (TITLE OF CLASS OF SECURITIES) 156431108 (CUSIP NUMBER) 12/31/2022 (DATE OF EVENT WHICH REQUIRES FILING OF THIS STATEMENT) CHECK THE APPROPRIATE BOX TO DESIGNATE THE RULE PURS

CENX / Century Aluminum Co / BlackRock Inc. Passive Investment

SC 13G/A 1 us1564311082012623.txt us1564311082012623.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: 2) CENTURY ALUMINUM CO - (Name of Issuer) Common Stock - (Title of Class of Securities) 156431108 - (CUSIP Number) December 31, 2022 - (Date of Event Which Requires Filing of this Statement) Check the appropriate bo

CENX / Century Aluminum Co / BlackRock Inc. Passive Investment

SC 13G/A 1 us1564311082011923.txt us1564311082011923.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: 1) CENTURY ALUMINUM CO - (Name of Issuer) Common Stock - (Title of Class of Securities) 156431108 - (CUSIP Number) December 31, 2022 - (Date of Event Which Requires Filing of this Statement) Check the appropriate bo

Table of Contents

EXHIBIT 12 Execution Version Termination Deed Dated 15 December 2022 GLENCORE AG and GIVOLON LIMITED and RYFOLD LIMITED Table of Contents Contents Page 1 Definitions and Interpretation 2 2 Termination of Agreements 3 3 Termination of Givolon Call Option Agreement and Givolon Shares SPA 5 4 Termination of the Framework Agreement (including the Joinder Agreement) 5 5 Termination of the Facility Agre

JOINT FILING AGREEMENT

EXHIBIT 1 JOINT FILING AGREEMENT Each of the undersigned hereby agrees that this Amendment No.

CENX / Century Aluminum Co / GLENCORE INTERNATIONAL AG - SC 13D/A Activist Investment

Page 1 of 17 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 26)* CENTURY ALUMINUM COMPANY Name of Issuer COMMON STOCK, $0.01 Par Value (Title of Class of Securities) 156431 10 8 (CUSIP Number) Steven Kalmin Glencore International AG Baarermattstrasse 3 CH-6340 Baar Switzerland +41 41 709 2000 With copi

CENX / Century Aluminum Co / Givolon Ltd - SC 13D/A Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 2)* CENTURY ALUMINUM COMPANY Name of Issuer COMMON STOCK, $0.01 Par Value (Title of Class of Securities) 156431 10 8 (CUSIP Number) Brendan Dowling Ocorian Limited 26 New Street St Helier, Jersey JE2 3RA +44 1534 844802 (Name, Address and Telephone Number

JOINT FILING AGREEMENT

EXHIBIT 1 JOINT FILING AGREEMENT Each of the undersigned hereby agrees that this Amendment No.

Table of Contents

EXHIBIT 19 Execution Version Termination Deed Dated 15 December 2022 GLENCORE AG and GIVOLON LIMITED and RYFOLD LIMITED Table of Contents Contents Page 1 Definitions and Interpretation 2 2 Termination of Agreements 3 3 Termination of Givolon Call Option Agreement and Givolon Shares SPA 5 4 Termination of the Framework Agreement (including the Joinder Agreement) 5 5 Termination of the Facility Agre

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 12, 2022 Century Aluminu

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 12, 2022 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission

Facility Agreement dated 9 December 2022 among Century Aluminum Vlissingen B.V. as borrower and Glencore international AG as lender

a2022centuryfacilityagre U.S.$90,000,000 Facility agreement Dated 9 December 2022 for CENTURY ALUMINUM VLISSINGEN B.V. as Borrower with GLENCORE INTERNATIONAL AG acting as Lender (i) CONTENTS CLAUSE PAGE INTERPRETATION 1. Definitions and Interpretation .................................................................................................... 1 SECTION 2 THE FACILITY 2. The Facility......

$MM (except shipments and per share data) Q2 2022 Q3 2022 Shipments (tonnes) 214,084 173,725 Net sales $ 856.6 $ 637.2 Net income $ 37.4 $ 44.3 Diluted earnings per share $ 0.36 $ 0.43 Adjusted net income/(loss)(1) $ 30.4 $ (34.2) Adjusted earnings/(

Exhibit 99.1 Century Aluminum Company Reports Third Quarter 2022 Results Chicago, November 7, 2022 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its third quarter 2022 results. Business Highlights ?Shipments down 19% sequentially related to the Hawesville curtailment ?Realized LME aluminum price of $2,636/T in third quarter is down $425/T from prior quarter ?Strong tot

Term Facility Agreement, dated as of September 29, 2022, by and between Nordural Grundartangi ehf, as borrower, and Arion Bank hf

Exhibit 10.2 29 SEPTEMBER 2022 Between NOR?UR?L GRUNDARTANGI EHF. (as Borrower) and ARION BANK HF. (as Lender) TERM FACILITY AGREEMENT 2 CONTENT 1 Definitions ................................................................................................................... 3 2 The Facility ............................................................................................................

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 7, 2022 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2022 ☐ TRANSITION REPORT PURSUANT

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2022 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-34474 Century Aluminu

Amendment to Revolving Credit Facility, dated September 28, 2022, between Nordural Grundartangi ehf, as borrower and Landsbankinn hf

1/2 Amendment Exhibit 10.1 0106-36-028285 to the Committed Revolving Credit Facility in the original amount of USD 50.000.000,-, between Nordural Grundartangi ehf., reg. no: 570297-2609, as the Borrower and Landsbankinn hf., reg. no. 471008-0280, as the Bank, dated November 27th 2013 as amended from time to time (hereinafter referred to as the "Agreement"). The Borrower and the Bank have agreed to

$MM (except shipments and per share data) Q1 2022 Q2 2022 Shipments (tonnes) 211,411 214,084 Net sales $ 753.6 $ 856.6 Net income $ 17.7 $ 37.4 Diluted earnings per share $ 0.18 $ 0.36 Adjusted net income(1) $ 60.7 $ 30.4 Adjusted earnings per share(

Exhibit 99.1 Century Aluminum Company Reports Second Quarter 2022 Results Chicago, August 9, 2022 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its second quarter 2022 results. Business Highlights ?Shipments up 1% sequentially ?Net sales up 14% sequentially on higher realized LME prices and regional premiums ?Realized LME aluminum price of $3,062/T in second quarter is

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2022 ☐ TRANSITION REPORT PURSUANT TO S

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2022 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-34474 Century Aluminum Com

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 9, 2022 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission Fil

Regulation FD Disclosure, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 1, 2022 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission Fil

Century Aluminum Appoints Gerald Bialek as Chief Financial Officer

Exhibit 99.1 Century Aluminum Appoints Gerald Bialek as Chief Financial Officer CHICAGO, August 1, 2022 (GLOBE NEWSWIRE) ? Century Aluminum Company (NASDAQ: CENX) announced today that it has appointed Gerald ?Jerry? Bialek as its new Executive Vice President and Chief Financial Officer. Mr. Bialek will join the Company on August 22, 2022 and will report directly to Century?s Chief Executive Office

Offer Letter dated as of July 27, 2022

Exhibit 10.1 July 27, 2022 Mr. Jerry Bialek 280 Ethyl Drive Brooklyn, MI 49230 Dear Jerry: We are very pleased to offer you the position of Executive Vice President and Chief Financial Officer of Century Aluminum Company (the ?Company?). In this position, you will be based out of the Company?s Chicago headquarters and will report directly to the Chief Executive Officer of Century Aluminum Company.

CENX / Century Aluminum Co / BlackRock Inc. Passive Investment

SC 13G 1 us1564311082070822.txt us1564311082070822.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: ) CENTURY ALUMINUM CO - (Name of Issuer) Common Stock - (Title of Class of Securities) 156431108 - (CUSIP Number) June 30, 2022 - (Date of Event Which Requires Filing of this Statement) Check the appropriate box to de

Century Aluminum to Temporarily Idle Its Hawesville Smelter Due to Soaring Energy Prices;

Exhibit 99.1 Century Aluminum to Temporarily Idle Its Hawesville Smelter Due to Soaring Energy Prices; Issues WARN Notice to Employees CHICAGO, June 22, 2022 (GLOBE NEWSWIRE) ? Century Aluminum Company (NASDAQ: CENX), the largest producer of primary aluminum in the United States, has announced it will temporarily idle its smelter in Hawesville, Kentucky, as a direct result of skyrocketing energy c

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 22, 2022 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File

Amendment No. 4 dated June 14, 2022 to the Second Amended and Restated Loan and Security Agreement, dated as of May 16, 2018, among Century Aluminum Company, Century Aluminum of South Carolina, Inc., Century Aluminum of Kentucky General Partnership, NSA General Partnership and Century Aluminum Sebree LCC, as borrowers, and Wells Fargo Capital Finance, LLC, as agent and lender.

Exhibit 10.1 AMENDMENT NO. 4 TO SECOND AMENDED AND RESTATED LOAN AND SECURITY AGREEMENT THIS AMENDMENT NO. 4 TO SECOND AMENDED AND RESTATED LOAN AND SECURITY AGREEMENT (this "Amendment") is entered into as of June 14, 2022, by and among the Lenders party hereto, WELLS FARGO CAPITAL FINANCE, LLC, a Delaware limited liability company, as the agent for the Lenders (in such capacity, "Agent"), Century

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 13, 2022 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File

As filed with the Securities and Exchange Commission on May 20, 2022

As filed with the Securities and Exchange Commission on May 20, 2022 Registration No.

Fee Table.

EX-FILING FEES 7 tm2214429d1ex-filingfees.htm EX-FILING FEES Exhibit 107.1 Calculation of Filing Fee Table FORM S-3 Registration Statement Under the Securities Act of 1933 (Form Type) Century Aluminum Company (Exact Name of Registrant as Specified in its Charter) Security Type Security Class Title(1) Fee Calculation or Carry Forward Rule Amount Registered(2) Proposed Maximum Offering Price Per Uni

Powers of Attorney

Exhibit 24.1 POWER OF ATTORNEY KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below, acting in the capacity or capacities stated with their respective names below, hereby constitutes and appoints John DeZee as his or her true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, for him or her and in his or her name, place and stea

Term Facility Amendment Agreement, dated November 12, 2021 between Nordural Grundartangi ehf and Arion Bank hf

Exhibit 10.1 TERM FACILITY AMENDMENT AGREEMENT THIS AGREEMENT is dated 12 November 2021 and made between: (1)NOR?UR?L GRUNDARTANGI EHF., a private limited liability company incorporated and registered in Iceland with the registration number 570297-2609 (the "Borrower"); and (2)ARION BANK HF., a limited liability company and licenced as a financial institution, incorporated and registered in Icelan

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2022 ☐ TRANSITION REPORT PURSUANT TO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2022 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-34474 Century Aluminum Co

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

DEFA14A 1 d330450ddefa14a.htm DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ? Filed by a Party other than the Registrant ? Check the appropriate box: ? Preliminary Proxy Statement ? Confidential, for Use of the Commission Only (as permitted by Rule 14

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): April 28, 2022 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission Fil

$MM (except shipments and per share data) Q4 2021 Q1 2022 Shipments (tonnes) 200,961 211,411 Net sales $ 659.1 $ 753.6 Net income $ 60.4 $ 17.7 Diluted earnings per share $ 0.59 $ 0.18 Adjusted net income(1) $ 17.2 $ 60.7 Adjusted earnings per share(

Exhibit 99.1 Century Aluminum Company Reports First Quarter 2022 Results Chicago, April 28, 2022 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its first quarter 2022 results. Business Highlights ?Shipments up 5% sequentially ?Net Sales up 14% sequentially on higher LME prices ?Global ~1 million tonnes supply deficit and lowest LME inventory levels since 2005 ?Realized

Powers of Attorney

EXHIBIT 24.1 POWER OF ATTORNEY I hereby constitute and appoint John DeZee and Leah Patterson as my true and lawful attorney-in-fact and agent, with full power of substitution, for me and in my name, in any and all capacities, to sign on my behalf the Annual Report on Form 10-K of Century Aluminum Company for the fiscal year ended December 31, 2021, and any amendment or supplement thereto; and to f

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE FISCAL YEAR ENDED DECEMBER 31, 2021 ☐ TRANSITION REPORT PURSUANT TO SECTI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ? ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE FISCAL YEAR ENDED DECEMBER 31, 2021 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number 001-34474 CENTURY ALUMINUM COMPANY (Exact name of registrant as specif

List of Subsidiaries

EXHIBIT 21.1 CENTURY ALUMINUM COMPANY Subsidiaries of the Registrant Company Name State or Other Jurisdiction of Incorporation or Organization Name Under Business is Conducted Century Aluminum of South Carolina, Inc. Delaware Century Aluminum of South Carolina, Inc. Century Aluminum Sebree, LLC Delaware Century Aluminum Sebree, LLC Century Marketer LLC Delaware Century Marketer LLC Century Califor

$MM (except shipments and per share data) Q3 2021 Q4 2021 Shipments (tonnes) 196,095 200,961 Net sales $ 581.4 $ 659.1 Net income (loss) $ (52.4) $ 60.4 Diluted earnings (loss) per share $ (0.58) $ 0.59 Adjusted net income (loss)(1) $ (5.7) $ 17.2 Ad

Exhibit 99.1 Century Aluminum Company Reports Fourth Quarter 2021 Results Chicago, February 24, 2022 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its fourth quarter and full year 2021 results. 2021 Business Highlights ?Realized LME aluminum price of $2,605/T in fourth quarter is up $230/T from prior quarter ?Realized regional premiums of $720/T and $340/T for U.S. Mid

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 24, 2022 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission

CENX / Century Aluminum Co / STATE STREET CORP Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 AMENDED FILING CENTURY ALUMINUM CO (NAME OF ISSUER) COMMON STOCK (TITLE OF CLASS OF SECURITIES) 156431108 (CUSIP NUMBER) 12/31/2021 (DATE OF EVENT WHICH REQUIRES FILING OF THIS STATEMENT) CHECK THE APPROPRIATE BOX TO DESIGNATE THE RULE PURSUANT TO WHICH THIS SCHEDULE IS FI

Amendment to Revolving Credit Facility, dated February 4, 2022, between Nordural Grundartangi ehf, as borrower and Landsbankinn hf

Exhibit 10.1 0106-36-028285 Amendment to the Committed Revolving Credit Facility in the amount of USD 50.000.000,-, between Nor?ur?l Grundartangi ehf., reg. no: 570297-2609, as the Borrower and Landsbankinn hf., reg. no. 471008-0280, as the Bank, dated November 27th 2013 as amended from time to time (hereinafter referred to as the ?Agreement?). The Borrower and the Bank have agreed to make the fol

CENX / Century Aluminum Co / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SC 13G/A 1 tv0025-centuryaluminumco.htm SCHEDULE 13G/A SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 2)* Name of issuer: Century Aluminum Co. Title of Class of Securities: Common Stock CUSIP Number: 156431108 Date of Event Which Requires Filing of this Statement: December 31, 2021 Check the appropriate box to design

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 4, 2022 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission F

CENX / Century Aluminum Co / DIMENSIONAL FUND ADVISORS LP - SEC SCHEDULE 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 10 )* Century Aluminum Co (Name of Issuer) Common Stock (Title of Class of Securities) 156431108 (CUSIP Number) December 31, 2021 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this S

Regulation FD Disclosure, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 1, 2022 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission F

Announces Departure of Chief Financial Officer; Senior Vice President, Finance to Assume Responsibilities of Principal Financial Officer During Search for Replacement

Exhibit 99.1 Century Announces Departure of Chief Financial Officer; Senior Vice President, Finance to Assume Responsibilities of Principal Financial Officer During Search for Replacement CHICAGO, February 4, 2022 (GLOBE NEWSWIRE) ? Century Aluminum Company (NASDAQ: CENX) announced today that Craig Conti will be leaving the Company in order to be closer to family and pursue other opportunities, ef

CENX / Century Aluminum Co / BlackRock Inc. Passive Investment

us1564311082020122.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: 6) CENTURY ALUMINUM CO - (Name of Issuer) Common Stock - (Title of Class of Securities) 156431108 - (CUSIP Number) December 31, 2021 - (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant t

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 23, 2021 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission

Amendment No. 3, dated as of December 23, 2021 to the Second Amended and Restated Loan and Security Agreement, dated as of May 16, 2018, among Century Aluminum Company, Century Aluminum of South Carolina, Inc., Century Aluminum of Kentucky General Partnership, NSA General Partnership and Century Aluminum Sebree LLC, as borrowers,

Exhibit 10.1 AMENDMENT NO. 3 TO SECOND AMENDED AND RESTATED LOAN AND SECURITY AGREEMENT THIS AMENDMENT NO. 3 TO SECOND AMENDED AND RESTATED LOAN AND SECURITY AGREEMENT (this "Amendment") is entered into as of December 23, 2021, by and among the Lenders party hereto, WELLS FARGO CAPITAL FINANCE, LLC, a Delaware limited liability company, as the agent for the Lenders (in such capacity, "Agent"), CEN

Regulation FD Disclosure, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 6, 2021 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission F

Century Aluminum Company Announces Jennifer Bush as New Independent Board Member

Exhibit 99.1 Century Aluminum Company Announces Jennifer Bush as New Independent Board Member CHICAGO, December 8, 2021 (GLOBE NEWSWIRE) ? Century Aluminum Company (NASDAQ: CENX) announced today that its Board of Directors (the ?Board?) increased the size of the Board from five to six members on December 6, 2021 and appointed Jennifer (?Jenny?) Bush as an independent director effective immediately

, between Nordural Grundartangi ehf, as borrower, and Landsbankinn hf

Exhibit 10.1 Amendment 0106-36-028285 to the Committed Revolving Credit Facility in the amount of USD 50.000.000,-, between Nor?ur?l Grundartangi ehf., reg. no: 570297-2609, as the Borrower, and Landsbankinn hf., reg. no. 471008-0280, as the Bank, dated November 27th 2013 (hereinafter referred to as the ?Agreement?). The Borrower and the Bank have agreed to make the following amendment to the Agre

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2021 ☐ TRANSITION REPORT PURSUANT

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2021 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-34474 Century Aluminu

Century Aluminum Announces Casthouse Expansion Project into Low Carbon Billet Production for its Grundartangi, Iceland smelter

Exhibit 99.1 Century Aluminum Announces Casthouse Expansion Project into Low Carbon Billet Production for its Grundartangi, Iceland smelter CHICAGO, November 3, 2021 (GLOBE NEWSWIRE) ? Century Aluminum Company (NASDAQ: CENX) announced today that its wholly-owned subsidiary, Nor?ur?l Grundartangi ehf (?Nor?ur?l?), has commenced construction of a new low-carbon billet casthouse at its Grundartangi,

$MM (except shipments and per share data) Q2 2021 as Presented Q2 2021 Updated(2)(3) Q3 2021 Shipments (tonnes) 190,894 190,894 196,095 Net sales $ 528.0 $ 528.0 $ 581.4 Net income (loss) $ (35.1) $ (35.1) $ (52.4) Diluted earnings (loss) per share $

Exhibit 99.1 Century Aluminum Company Reports Third Quarter 2021 Results Chicago, November 3, 2021 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its third quarter 2021 results. Business Highlights ?Realized LME aluminum price of $2,375/T in third quarter is up $220/T from prior quarter ?Realized regional premiums of $670/T and $245/T for U.S. Midwest and EU Duty Paid,

Regulation FD Disclosure, Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 2, 2021 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission F

Term Facility Agreement, dated as of November 2, 2021, between Nordural Grundartangi ehf and Arion Bank hf.

Exhibit 10.1 2 November 2021 Between NOR?UR?L GRUNDARTANGI EHF. (as Borrower) and ARION BANK HF. (as Lender) TERM FACILITY AGREEMENT 1 CONTENT 1 Definitions 4 2 The Facility 14 3 Purpose 14 4 Conditions precedent 15 5 Drawdown 15 6 Interest 16 7 Repayment 18 8 Prepayment and cancellation 18 9 Payments 20 10 Fees, Charges and Expenses 20 11 Additional payment obligations 21 12 Representations, warr

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 3, 2021 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission F

to the Second Amended and Restated Loan and Security Agreement, dated as of May 16, 2018, among Century Aluminum Company, Century Aluminum of South Carolina, Inc., Century Aluminum of Kentucky General Partnership, NSA General Partnership and Century Aluminum Sebree LCC, as borrowers, and Wells Fargo Capital Finance, LLC, as agent and lender.

Exhibit 10.1 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED LOAN AND SECURITY AGREEMENT THIS AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED LOAN AND SECURITY AGREEMENT (this "Amendment") is entered into as of June 15, 2021, by and among the Lenders party hereto, WELLS FARGO CAPITAL FINANCE, LLC, a Delaware limited liability company, as the agent for the Lenders (in such capacity, "Agent"), CENTURY

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2021 ☐ TRANSITION REPORT PURSUANT TO S

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2021 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-34474 Century Aluminum Com

$MM (except shipments and per share data) Q1 2021 Q2 2021 Shipments (tonnes) 195,697 190,894 Net sales $ 444.0 $ 528.0 Net income (loss) $ (140.0) $ (35.1) Diluted earnings (loss) per share $ (1.55) $ (0.39) Adjusted net income (loss)(1) $ (52.5) $ (

Exhibit 99.1 Century Aluminum Company Reports Second Quarter 2021 Results Chicago, August 4, 2021 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its second quarter 2021 results. Business Highlights ?Realized LME aluminum price of $2,155/T in second quarter is up $215/T from prior quarter ?Realized regional premiums of $490/T and $175/T for U.S. Midwest and EU Duty Paid,

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 4, 2021 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission Fil

CENX / Century Aluminum Co / STATE STREET CORP Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 AMENDED FILING CENTURY ALUMINUM CO (NAME OF ISSUER) COMMON STOCK (TITLE OF CLASS OF SECURITIES) 156431108 (CUSIP NUMBER) 06/30/2021 (DATE OF EVENT WHICH REQUIRES FILING OF THIS STATEMENT) CHECK THE APPROPRIATE BOX TO DESIGNATE THE RULE PURSUANT TO WHICH THIS SCHEDULE IS FI

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 14, 2021 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 26, 2021 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File

Century Aluminum Announces CEO Succession

Exhibit 99.1 Century Aluminum Announces CEO Succession Mike Bless to Retire; Jesse Gary Named Next President and CEO of Century Aluminum, Effective July 1, 2021 CHICAGO, May 17, 2021 (GLOBE NEWSWIRE) ? Century Aluminum Company (NASDAQ: CENX) announced today that Mike Bless will retire as President and Chief Executive Officer, effective July 1, 2021, after 15 years with Century, including nearly 10

Jesse E. Gary Offer Letter, dated May 17, 2021

Exhibit 10.1 May 17, 2021 Mr. Jesse E. Gary 1204 Michigan Ave. Wilmette, IL 60091 Dear Jesse: We are very pleased to offer you the position of President and Chief Executive Officer of Century Aluminum Company (the ?Company?), effective July 1, 2021 (the ?CEO Date?). In this position, you will continue to be based out of the Company?s Chicago headquarters and will report directly to the Company?s B

Regulation FD Disclosure, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 17, 2021 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Ame

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confide

Retirement and Transition Agreement, dated May 17, 2021, between Century Aluminum Company and Michael A. Bless

Exhibit 10.2 EXECUTION VERSION RETIREMENT AND TRANSITION AGREEMENT This RETIREMENT AND TRANSITION AGREEMENT (this ?Agreement?) is entered into by and between Century Aluminum Company, a Delaware corporation (the ?Company?), and Michael A. Bless (?Executive?), dated May 17, 2021 (the ?Effective Date?). RECITALS: WHEREAS, Executive currently serves as President and Chief Executive Officer (the ?CEO?

Quarterly Report - 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2021 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-34474 Century Aluminum Co

$MM (except shipments and per share data) Q4 2020 Q1 2021 Shipments (tonnes) 194,940 195,697 Net sales $ 389.1 $ 444.0 Net income (loss) $ (35.5) $ (140.0) Diluted earnings (loss) per share $ (0.40) $ (1.55) Adjusted net income (loss)(1) $ (30.6) $ (

Exhibit 99.1 Century Aluminum Company Reports First Quarter 2021 Results Chicago, May 5, 2021 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its first quarter 2021 results. First Quarter 2021 Financial Results ?Shipments of 195,697 tonnes ?Net sales of $444.0 million ?Net loss of $(140.0) million, or $(1.55) per share ?Adjusted net loss(1) of $(52.5) million, or $(0.54)

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 5, 2021 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File N

- DEF 14A - 2021 PROXY STATEMENT

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confide

- DEFA14A - NOTICE OF PROXY

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confide

Entry into a Material Definitive Agreement, Termination of a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): April 14, 2021 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission Fil

Second Lien Pledge and Security Agreement, dated as of April 14, 2021 by and among Century Aluminum Company, the other Grantors (as defined therein) and Wilmington Trust, National Association, as collateral agent.

Exhibit 10.1 ========================================================== SECOND LIEN PLEDGE AND SECURITY AGREEMENT dated as of April 14, 2021 among CENTURY ALUMINUM COMPANY, the other Grantors party hereto and WILMINGTON TRUST, NATIONAL ASSOCIATION, as Collateral Agent Notwithstanding anything herein to the contrary, the liens and security interests granted to the COLLATERAL Agent pursuant to this

Collateral Agency Agreement, dated as of April 14, 2021, by and among Century Aluminum Company, the other Grantors (as defined therein) and Wilmington Trust, National Association, as trustee and collateral agent.

EX-10.2 4 exhibit102-collateralagenc.htm EX-10.2 - COLLATERAL AGENCY AGREEMENT Exhibit 10.2 COLLATERAL AGENCY AGREEMENT Dated as of April 14, 2021 among CENTURY ALUMINUM COMPANY, THE OTHER GRANTORS PARTY HERETO, WILMINGTON TRUST, NATIONAL ASSOCIATION, as trustee under the Senior Secured Note Indenture, and WILMINGTON TRUST, NATIONAL ASSOCIATION, as Collateral Agent TABLE OF CONTENTS PAGE SECTION 1

Form of 7.5% Note for the Indenture for Century Aluminum Company’s 7.5% Senior Secured Notes due 2028, dated as of April 14, 2021, by and among Century Aluminum Company, the guarantors party thereto and Wilmington Trust, National Association, as trustee and noteholder collateral agent (incorporated by reference to Exhibit 4.2 to Century Aluminum’s Current Report on Form 8-K filed on April 15, 2021).

Exhibit 4.1 CENTURY ALUMINUM COMPANY, as Issuer the GUARANTORS party hereto and WILMINGTON TRUST, National Association, as Trustee and Noteholder Collateral Agent Indenture Dated as of April 14, 2021 7.5% Senior Secured Notes due 2028 CROSS-REFERENCE TABLE TIA Sections Indenture Sections 310(a)(1) 7.10 (a)(2) 7.10 (a)(3) Not Applicable (a)(4) Not Applicable (a)(5) 7.10 (b) 7.03; 7.08; 7.10 (c) Not

Form of Capped Call Confirmation

Exhibit 10.1 To: Century Aluminum Company One South Wacker Drive Suite 1000 Chicago, Illinois 60606 From: [Dealer] Re: [Base][Additional] Capped Call Transaction Date: [], 2021 Dear Ladies and Gentlemen: The purpose of this communication (this ?Confirmation?) is to set forth the terms and conditions of the above-referenced transaction entered into on the Trade Date specified below (the ?Transactio

Entry into a Material Definitive Agreement, Unregistered Sales of Equity Securities, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): April 6, 2021 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File

Form of Note for the Indenture for Century Aluminum Company’s 2.75% Convertible Senior Notes due 2028, dated as of April 9, 2021, between Century Aluminum Company, as issuer, and Wilmington Trust Company, as trustee (incorporated by reference to Exhibit 4.2 to Century Aluminum’s Current Report on Form 8-K filed on April 12, 2021).

Exhibit 4.1 CENTURY ALUMINUM COMPANY AND WILMINGTON TRUST, NATIONAL ASSOCIATION, as Trustee INDENTURE Dated as of April 9, 2021 2.75% Convertible Senior Notes due 2028 TABLE OF CONTENTS Page ARTICLE 1 DEFINITIONS Section 1.01. Definitions 1 Section 1.02. References to Interest 13 ARTICLE 2 ISSUE, DESCRIPTION, EXECUTION, REGISTRATION AND EXCHANGE OF NOTES Section 2.01. Designation and Amount 13 Sec

CENTURY ALUMINUM COMPANY ANNOUNCES PROPOSED CONCURRENT PRIVATE OFFERINGS OF SENIOR SECURED NOTES AND CONVERTIBLE SENIOR NOTES

Exhibit 99.1 CENTURY ALUMINUM COMPANY ANNOUNCES PROPOSED CONCURRENT PRIVATE OFFERINGS OF SENIOR SECURED NOTES AND CONVERTIBLE SENIOR NOTES CHICAGO, IL?April 5, 2021?Century Aluminum Company (NASDAQ: CENX) (?Century?) announced today a proposed private offering of $250 million aggregate principal amount of senior secured notes due April 2028 (the ?Secured Notes?), subject to market and other condit

Title of Notes

Exhibit 99.2 CENTURY ALUMINUM COMPANY ANNOUNCES CASH TENDER OFFER FOR ITS 12.0% SENIOR SECURED NOTES DUE 2025 CHICAGO, IL? April 5, 2021? Century Aluminum Company (NASDAQ: CENX) (?Century?) today announced the commencement of a cash tender offer (the ?Tender Offer?) to purchase any and all of Century?s 12.0% Senior Secured Notes due 2025 (the ?Notes?). The Tender Offer is being made pursuant to an

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): April 5, 2021 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File

Century Aluminum Finalizes Mt. Holly Power Contract; Restart Project On Schedule

Exhibit 99.1 Century Aluminum Finalizes Mt. Holly Power Contract; Restart Project On Schedule Provides Updated 2021 Outlook CHICAGO, March 25, 2021 (GLOBE NEWSWIRE) ? Century Aluminum of South Carolina (CASC), a wholly-owned subsidiary of Century Aluminum Company (NASDAQ: CENX), announced today it has finalized, and received all necessary approvals for, its new, three-year power contract with the

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 25, 2021 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission Fil

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 8, 2021 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission File

List of Subsidiaries

EXHIBIT 21.1 CENTURY ALUMINUM COMPANY Subsidiaries of the Registrant Company Name State or Other Jurisdiction of Incorporation or Organization Name Under Business is Conducted Century Aluminum of South Carolina, Inc. Delaware Century Aluminum of South Carolina, Inc. Century Aluminum Sebree, LLC Delaware Century Aluminum Sebree, LLC Century Marketer LLC Delaware Century Marketer LLC Century Califor

Annual Report - 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ? ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE FISCAL YEAR ENDED DECEMBER 31, 2020 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number 001-34474 CENTURY ALUMINUM COMPANY (Exact name of registrant as specif

Powers of Attorney

EXHIBIT 24.1 POWER OF ATTORNEY I hereby constitute and appoint Jesse E. Gary and Morgan F. Walbridge as my true and lawful attorney-in-fact and agent, with full power of substitution, for me and in my name, in any and all capacities, to sign on my behalf the Annual Report on Form 10-K of Century Aluminum Company for the fiscal year ended December 31, 2020, and any amendment or supplement thereto;

$MM (except shipments and per share data) Q3 2020 Q4 2020 FY 2019 FY 2020 Shipments (tonnes) 203,022 194,940 811,244 811,176 Net sales $ 392.9 $ 389.1 $ 1,836.6 $ 1,605.1 Net income (loss) $ (58.2) $ (35.5) $ (80.8) $ (123.3) Diluted earnings (loss)

Exhibit 99.1 Century Aluminum Company Reports Fourth Quarter and Full year 2020 Results Chicago, February 18, 2021 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its fourth quarter and full year 2020 results. Fourth Quarter 2020 Financial Results ?Shipments of 194,940 tonnes ?Net sales of $389.1 million ?Net loss of $(35.5) million, or $(0.40) per share ?Adjusted net lo

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 18, 2021 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission

SCHEDULE 13G

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 9 )* Century Aluminum Co (Name of Issuer) Common Stock (Title of Class of Securities) 156431108 (CUSIP Number) December 31, 2020 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Sc

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 8, 2021 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission F

Century Aluminum Names Gunnar Gudlaugsson Executive Vice President, Global Operations

Exhibit 99.1 Century Aluminum Names Gunnar Gudlaugsson Executive Vice President, Global Operations John Hoerner, Century?s EVP North America Operations, to Retire CHICAGO, Feb. 09, 2021 (GLOBE NEWSWIRE) ? Century Aluminum Company (NASDAQ: CENX) announced today that it has named Gunnar Gudlaugsson as Executive Vice President, Global Operations. Since joining Century in 2008, Mr. Gudlaugsson has ser

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 1)*

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 1)* Name of issuer: Century Aluminum Co. Title of Class of Securities: Common Stock CUSIP Number: 156431108 Date of Event Which Requires Filing of this Statement: December 31, 2020 Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

SC 13G

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 ANNUAL FILING CENTURY ALUMINUM CO (NAME OF ISSUER) COMMON STOCK (TITLE OF CLASS OF SECURITIES) 156431108 (CUSIP NUMBER) 12/31/2020 (DATE OF EVENT WHICH REQUIRES FILING OF THIS STATEMENT) CHECK THE APPROPRIATE BOX TO DESIGNATE THE RULE PURSUANT TO WHICH THIS SCHEDULE IS FIL

SC 13G/A

us1564311082012821.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: 5) CENTURY ALUMINUM CO - (Name of Issuer) Common Stock - (Title of Class of Securities) 156431108 - (CUSIP Number) December 31, 2020 - (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant t

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers - 8-K RESIGNATION OF CARROLL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): January 29, 2021 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission F

Financial Statements and Exhibits, Other Events - 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 7, 2020 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission F

Century Aluminum Announces Preliminary Agreement with Santee Cooper for New Power Contract

Exhibit 99.1 Century Aluminum Announces Preliminary Agreement with Santee Cooper for New Power Contract New Contract Would Enable Mt. Holly to Expand Production and Hire 70 Employees CHICAGO, Dec. 7, 2020 (GLOBE NEWSWIRE) – Century Aluminum of South Carolina (CASC), a wholly-owned subsidiary of Century Aluminum Company (NASDAQ: CENX), announced today it has reached a preliminary agreement on the p

Quarterly Report - 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2020 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number 001-34474 Century Aluminu

Financial Statements and Exhibits, Results of Operations and Financial Condition - 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): October 29, 2020 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission F

$MM (except shipments and per share data) Q2 2020 Q3 2020 Shipments (tonnes) 210,309 203,022 Net sales $ 401.9 $ 392.9 Net income (loss) $ (26.9) $ (58.2) Diluted earnings (loss) per share $ (0.30) $ (0.65) Adjusted net income (loss)(1) $ (18.4) $ (6

Exhibit 99.1 Century Aluminum Company Reports Third Quarter 2020 Results Chicago, October 29, 2020 (GLOBE NEWSWIRE) - Century Aluminum Company (NASDAQ: CENX) today announced its third quarter 2020 results. Third Quarter 2020 Financial Results •Shipments of 203,022 tonnes, a 3% decrease over prior quarter •Net sales of $392.9 million •Net loss of $(58.2) million, or $(0.65) per share •Adjusted net

Century Issues WARN Notice at Mt. Holly, SC Smelter

Exhibit 99.1 Century Issues WARN Notice at Mt. Holly, SC Smelter Plant to be Curtailed Unless New Power Arrangement Reached Chicago, October 20, 2020 (GLOBE NEWSWIRE) - Century Aluminum of South Carolina, a wholly-owned subsidiary of Century Aluminum Company (NASDAQ: CENX), today issued a notice to employees at its Mt. Holly, South Carolina aluminum smelter of its intent to curtail plant operation

Financial Statements and Exhibits, Other Events - 8-K - MT. HOLLY WARN NOTICE

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): October 20, 2020 Century Aluminum Company (Exact Name of Registrant as Specified in Charter) Delaware 001-34474 13-3070826 (State or Other Jurisdiction of Incorporation) (Commission F

JOINT FILING AGREEMENT

EXHIBIT 1 JOINT FILING AGREEMENT Each of the undersigned hereby agrees that this Amendment No.

CENX / Century Aluminum Co. / GLENCORE INTERNATIONAL AG - SC 13D/A Activist Investment

Page 1 of 16 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 25)* CENTURY ALUMINUM COMPANY Name of Issuer COMMON STOCK, $0.01 Par Value (Title of Class of Securities) 156431 10 8 (CUSIP Number) Steven Kalmin Glencore International AG Baarermattstrasse 3 CH-6340 Baar Switzerland +41 41 709 2000 With copi

CENX / Century Aluminum Co. / GLENCORE INTERNATIONAL AG - SC 13D/A Activist Investment

Page 1 of 17 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 24)* CENTURY ALUMINUM COMPANY Name of Issuer COMMON STOCK, $0.01 Par Value (Title of Class of Securities) 156431 10 8 (CUSIP Number) Steven Kalmin Glencore International AG Baarermattstrasse 3 CH-6340 Baar Switzerland +41 41 709 2000 With copi

JOINT FILING AGREEMENT

EXHIBIT 99.1 JOINT FILING AGREEMENT Each of the undersigned hereby agrees that this Amendment No. 24 to the statement on Schedule 13D is being filed with the Securities and Exchange Commission on behalf of each of the undersigned pursuant to Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended. Date: August 20, 2020 Glencore AG By: /s/ Martin Haering Name: Martin Haering Title: Dire