Roswell Leavitt Gilpatric was a New York City corporate attorney and government official who served as Deputy Secretary of Defense from 1961–64, when he played a pivotal role in the high-stake strategies of the Cuban Missile Crisis, advising President John F. Kennedy as well as Robert McNamara and McGeorge Bundy on dealing with the Soviet nuclear missile threat. Gilpatric later served as Chairman of the Task Force on Nuclear Proliferation in 1964.

The deputy secretary of defense is a statutory office and the second-highest-ranking official in the Department of Defense of the United States of America.