Harold Varmus is an American Nobel Prize-winning scientist and the 14th and current Director of the National Cancer Institute, a post he was appointed to by President Barack Obama. He was a co-recipient (along with J. Michael Bishop) of the 1989 Nobel Prize in Physiology or Medicine for discovery of the cellular origin of retroviral oncogenes. He also serves as one of three co-Chairs of the President's Council of Advisors on Science and Technology.

From 1993 to 1999, he served as Director of the National Institutes of Health. As the NIH director, Varmus was credited with nearly doubling the research agency's budget. From 2000 to 2010, he served as President of Memorial Sloan-Kettering Cancer Center in New York City.

Beginning during his tenure as NIH director, Varmus has been a champion of an open access system for scientific papers, arguing that scientists should have control over the dissemination of their research rather than journal editors.