Chintamani Nagesa Ramachandra Rao, (born 30 June 1934), is an Indian chemist who has worked mainly in solid-state and structural chemistry. He has honorary doctorates from 84 universities from around the world and has authored around 1,774 research publications and 56 books. He is described as a scientist who had won all possible awards in his field except the Nobel Prize.

A precocious child, Rao completed BSc from Mysore University at age seventeen, and MSc from Banaras Hindu University at age nineteen. He earned a PhD from Purdue University at the age of twenty-four. He was the youngest lecturer when he joined the Indian Institute of Science in 1959. After a transfer to Indian Institute of Technology Kanpur, he returned to IISc, eventually becoming its Director from 1984 to 1994. He was chair of the Scientific Advisory Council to the Prime Minister of India from 1985 to 1989 and from 2005 to 2014. He founded and works in Jawaharlal Nehru Centre for Advanced Scientific Research and International Centre for Materials Science.

Rao received most important scientific awards and honours including the Marlow Medal, Shanti Swarup Bhatnagar Prize for Science and Technology, Hughes Medal, India Science Award, Dan David Prize, Royal Medal, Von Hippel Award, and ENI award. He also received Padma Shri and Padma Vibhushan from the Government of India. On 16 November 2013, the Government of India selected him for Bharat Ratna, the highest civilian award in India, making him the third scientist after C.V. Raman and A. P. J. Abdul Kalam to receive the award. He received the award on 4 February 2014 from President Pranab Mukherjee at the Rashtrapati Bhavan.