Robert Klein (born February 8, 1942) is a Jewish-American stand-up comedian and occasional actor.
Klein studied drama at Yale University when he got wind of an opportunity to audition for The Second City. In a piece he wrote for the improvisational troupe's book, Klein recalled sitting in a room full of other hopefuls including Fred Willard. Klein's audition consisted of an improvisation set with Willard about two guys in a nightclub, which was successful enough to get Klein and Willard hired to join Second City. Klein had said another young man, Billy Dee Williams, was hired to join the troupe but turned it down.
His first major appearance was as host of the 1970 summer replacement television series Comedy Tonight, on which were introduced many of the routines that in the next few years would be released on record albums. His extensive routines about the Watergate scandal made him highly popular in the 1970s. He was one of the first observational comedians.
Klein appeared in several stand-up comedy specials on HBO dating to its very early broadcast days. He has traditionally concluded these shows with his "I can't stop my leg" routine.
He attended Alfred University.