David Baltimore (born March 7, 1938) is an American biologist and the Nobel Prize winner for Physiology or Medicine.

He received the Nobel prize in 1975, at the age of 37. Baltimore has profound influence on national policy in matters concerning recombinant DNA research and the AIDS epidemic. Baltimore is currently the president of the California Institute of Technology (1997-present).

His Nobel prize work involved the discovery that RNA can be reversely transcribed (by reverse transcriptase) into DNA, upsetting what was until the early 70's a widely held dogma that DNA solely led to RNA which in turn solely led to DNA.