She was a professor of archaeology and ancient history at the Centre for Historical Studies at the Jawaharlal Nehru University, Delhi, and is currently an independent researcher living in Mumbai. She is noted for work on investigating the factors contributing to the end of the Indus Valley Civilization. Ratnagar was educated at Deccan College, Pune, University of Pune. She studied Mesopotamian archaeology at the Institute of Archaeology, University College London, and has field experience in Turkey, Iraq and the Persian Gulf.

Shereen Ratnagar belongs to a coterie of ideologically-inclined Indian academics sarcastically referred to as 'eminent historians' by their detractors such as Arun Shourie, although she is somewhat lower in the hierarchy led by Romila Thapar and Irfan Habib.

Arun Shourie and others hold the 'eminent historians' responsible for forming a clique that monopolized and distorted Indian historical research by suppressing any critique of the Leftist-Communist narrative espoused by them. The 'eminent historians' term their critics across the ideological spectrum as "fascists" and "extremists".

Shereen Ratnagar is part of a 'memorial commitee' for a member of a violent Maoist outfit that seeks to overthrow the democratic-elected Government of India and replace it with a hardcore Communist regime.

In its judgement on the long-standing Ram Janmabhoomi dispute, the Allahabad High Court flayed the role played by some witnesses including Ms. Ratnagar who was forced to admit that she had no field expertise in archeological excavations.

Earlier in the case, Shereen Ratnagar was served a contempt notice for violating a court order restraining witnesses in the ongoing case from airing their views in public.