Leslie "Les" Aspin, Jr. (July 21, 1938 – May 21, 1995) was a United States Representative from 1971 to 1993, and the United States Secretary of Defense under President Bill Clinton from January 21, 1993 to February 3, 1994.
Aspin was born in Milwaukee, Wisconsin. He graduated from Shorewood High School. He attended Yale University, where he was admitted to the Zeta Psi fraternity, and graduated summa cum laude in 1960 with a Bachelor of Arts in history. In 1962, he received his Master of Arts in economics from Oxford University, where he was a Rhodes Scholar, and his Ph.D in economics from the Massachusetts Institute of Technology in 1966.
As an officer in the U.S. Army from 1966 to 1968, he served as a systems analyst in the Pentagon under Secretary of Defense Robert S. McNamara. Before his election as a Democrat to Congress in 1970, Aspin had been active in Wisconsin politics and had taught economics at Marquette University.