Sankar Adhya (born 4 October 1937) is a molecular biologist and geneticist at the National Cancer Institute (NCI) and a member of the National Academy of Sciences.
He is best known for his work on bacterial transcription and the biology of bacteriophage lambda.
He has made important contributions regarding the physical basis of transcriptional regulation in bacteria, the lysis/lysogeny switch in lambda phage, the organization of the bacterial nucleoid, and phage therapy.