Rosemary Antonopoulos
Senior Vice President and Chief Administrative Officer
Rosemary Antonopoulos has served as Calpine’s Senior Vice President and Chief Administrative Officer since March 2025. In this role, she oversees the Company’s Corporate Communications, Cyber Security, Facilities, Human Resources, Physical Security and Administrative CCS Project Management organizations. Prior to her current role, Ms. Antonopoulos was Senior Vice President Administrative Services.
Before joining the administrative services organization, Ms. Antonopoulos served as Vice President and Deputy General Counsel for Calpine’s West region where she led Calpine’s West legal team responsible for supporting the Company’s West origination and commercial transactions; gas-fired and geothermal power operations; and construction and development of gas-fired, battery and Carbon Capture and Sequestration projects.
Ms. Antonopoulos joined Calpine in 2004 as Associate Counsel, later became Managing Counsel and, in 2009, was promoted to Vice President and Assistant General Counsel. Prior to joining Calpine, she was an attorney at a San Francisco-based law firm practicing energy development, construction and project finance law.
Ms. Antonopoulos holds a Bachelor of Arts in International Relations from Marquette University where she earned Phi Beta Kappa distinction and graduated magna cum laude. She received her law degree from George Washington University Law School.