Rudolph "Rudy" F. de Leon (born August 28, 1952) is an American former senior Department of Defense official, military adviser, lobbyist, and foreign policy adviser. He served as the Deputy Secretary of Defense, described as the "second-highest civilian defense position", from March 31, 2000 until March 16, 2001, and before appointed as Deputy Secretary he had served as Under Secretary of Defense for Personnel and Readiness from 1997 until 2000 and as Under Secretary of the Air Force from 1994 to 1997 in the administration of Bill Clinton.