X0508 4 2025-12-31 0 0000949157 CENTURY ALUMINUM CO CENX 0001568817 Gary Jesse E C/O CENTURY ALUMINUM COMPANY 1 S. WACKER DRIVE, SUITE 1000 CHICAGO IL 60606 1 1 0 0 President and CEO 0 Common Stock 2025-12-31 4 A 0 439090 0 A 805237 D Common Stock 2025-12-31 4 F 0 203131 39.18 D 602106 D Common Stock 2025-12-31 4 F 0 67711 39.18 D 534395 D Common Stock 2026-01-01 4 A 0 57443 0 A 591838 D Common Stock 127969 I By Trust Represents shares of common stock acquired by the Reporting Person upon the vesting of PSUs granted in connection with the Issuer's 2023-2025 Long-Term Incentive Plan under Rule 16b-3(d). Shares withheld by the Issuer to satisfy tax obligations in connection with the vesting of PSUs granted to the Reporting Person. Shares withheld by the Issuer to satisfy tax obligations in connection with the vesting of RSUs previously granted to the Reporting Person on January 1, 2023. Represents RSUs granted to the Reporting Person in connection with the Issuer's 2026-2028 Long-Term Incentive Plan under Rule 16b-3(d), all of which will vest on December 31, 2028, subject to the Plan's terms and conditions. Includes unvested RSUs granted to the Reporting Person under the Issuer's Long-Term Incentive Plans. Shares held in a self-settled, revocable trust for which the Reporting Person serves as trustee. /s/ Paul Sharobeem, attorney-in-fact for Jesse E. Gary 2026-01-05