Sivaraj Ramseshan (October 10, 1923 – December 29, 2003) was an Indian scientist known for his work in the field of crystallography. Ramaseshan served as Director of the Indian Institute of Science and was awarded the Padma Bhushan. Ramaseshan is the nephew of Indian scientist and Nobel laureate Sir C. V. Raman and cousin of Subramanyan Chandrasekhar.
Ramaseshan was born on October 10, 1923 in Madras to Sitalakshmi, sister of Indian scientist Sir C. V. Raman. He had his schooling in Nagpur and started his forays into science as a research student under his uncle, Sir C. V. Raman.
On completion of his doctorate, Ramaseshan joined the Indian Institute of Science as a lecturer. During this time, he developed an interest in X-ray crystallography and was instrumental in improving the material science division in the National Aerospace Laboratories. Ramaseshan also taught as a professor in the Indian Institute of Technology.
In 1979, Ramaseshan was appointed Joint-Director of the Indian Institute of Science and in 1981 became its Director. He served as the Director of IISc from 1981 to 1984, as President of the Indian Academy of Sciences (1983-85), and Honorary Distinguished Professor Emeritus at the Raman Research Institute (1984-2003).
In 1966, Ramaseshan was awarded the Shanti Swarup Bhatnagar Award. This was followed by the Vasvik Award in 1980 and the INSA Aryabhata Medal in 1985.Ramaseshan is also a recipient of the Padma Bhushan.
Ramaseshan died on December 29, 2003 at the age of 80.
Ramaseshan was married to Kausalya, great granddaughter of V. S. Srinivasa Sastri.
Ramaseshan is also acclaimed to be a good author. He wrote a biography of his uncle Sir C. V. Raman.