James Rodney Schlesinger (born February 15, 1929) was United States Secretary of Defense from 1973 to 1975 under presidents Richard Nixon and Gerald Ford. He became America's first Secretary of Energy under Jimmy Carter.

While Secretary of Defense, he opposed amnesty for draft dodgers, and pressed for development of more sophisticated nuclear weapon systems. Additionally, his support for the A-10 and the lightweight fighter program (later the F-16) helped ensure that they were carried to completion.

Schlesinger was born in New York City, the son of Rae, a Russian Jewish immigrant, and Julius Schlesinger, an Austrian Jew. He was educated at Horace Mann School and Harvard University, where he earned a B.A. (1950), M.A. (1952), and Ph.D. (1956) in economics. Between 1955 and 1963 he taught economics at the University of Virginia and in 1960 published The Political Economy of National Security. In 1963 he moved to the Rand Corporation, where he worked until 1969, in the later years as director of strategic studies.