G. Madhavan Nair (born 31 October 1943) is an Indian space scientist and a former Chairman of the Indian Space Research Organisation, and Secretary to the Department of Space, Government of India. He has also been the Chairman of the Space Commission and Chairman of the Governing Body of the Antrix Corporation, Bangalore. He was Chairman of the Board of Governors of the Indian Institute of Technology Patna until he stepped down due to his involvement in a controversial deal relating to sale of radio spectrum bandwidth involving Antrix. He was subsequently barred from holding any government positions.