Shyam Sunder Kapoor (born 14 June 1938) is an Indian nuclear physicist and a former director of Bhabha Atomic Research Centre. Known for his research on fission and heavy-ion physics, Kapoor is an elected fellow of all the three major Indian science academies – Indian Academy of Sciences, Indian National Science Academy and National Academy of Sciences, India – as well as the Institute of Physics. The Council of Scientific and Industrial Research, the apex agency of the Government of India for scientific research, awarded him the Shanti Swarup Bhatnagar Prize for Science and Technology, one of the highest Indian science awards, for his contributions to Physical Sciences in 1983. S. S. Kapoor, born on 14 June 1938, earned an MSc from Agra University in physics in 1958 before starting his career in 1959 at Bhabha Atomic Research Centre (then known as Atomic Energy Establishment). While on service, he pursued his doctoral studies mentored by Raja Ramanna, who would later spearhead India's first successful nuclear program, Smiling Buddha, in 1974. After securing a PhD in 1963, he took a sabbatical from work and did his post-doctoral studies in nuclear fission at Lawrence Berkeley National Laboratory of the University of California, Berkeley from 1964 where he worked at the cyclotron accelerator and returned to BARC in 1966 to resume his service. He became the director in charge of Physics Group as well as Electronics and Instrumentation Group in 1990 and served out his regular service at BARC, holding the position until his superannuation in 2000. He also served as the head of the nuclear physics division and as the project director of Pelletron Accelerator facility, a BARC centre located in Tata Institute of Fundamental Research campus. In between, he had a short stint abroad as a visiting scientist at Physikalische Institute of the University of Heidelberg during 1980–81. Post-retirement, he continued his association with BARC, holding the DAE-Homi Bhabha chair from 2000 to 2005.