Varun Srinivasan Sivaram is an American physicist, clean energy executive, and former U.S. diplomat. He is Group Senior Vice President, member of the Group Executive Team, and Head of Strategy, Innovation, Portfolio, and Partnerships and M&A at Ørsted, a clean energy company with the world's largest offshore wind energy portfolio. He has previously served in the U.S. State Department as managing director for clean energy and senior advisor to U.S. Special Presidential Envoy for Climate John Kerry, as the chief technology officer (CTO) of ReNew Power, India's largest renewable energy company, on the faculty of Columbia University, as the director of the energy and climate program at the Council on Foreign Relations (CFR), and as a senior energy advisor to the mayor of Los Angeles and governor of New York.