Robert Klein (born February 8, 1942) is an American stand-up comedian, singer, and actor. He is known for his appearances on stage and screen. He has released four standup comedy specials including, A Child of the 50s (1973), Mind Over Matter (1974), New Teeth (1975), and Let's Not Make Love (1990). The first two albums received Grammy Award for Best Comedy Album nominations. Klein hosted Saturday Night Live in its first season in 1975 and again in 1978. Klein made his Broadway debut in the 1966 production of The Apple Tree opposite Alan Alda. He earned a Tony Award for Best Actor in a Musical nomination for his performance in Neil Simon's musical comedy They're Playing Our Song (1979).

He is known for his film roles in The Owl and the Pussycat (1970), Mixed Nuts (1994), One Fine Day (1996), Primary Colors (1998), Two Weeks Notice (2002), How to Lose a Guy in 10 Days (2003), and Reign Over Me (2007). He is also known for his recurring television roles in Law & Order: SVU (2009-2012), The Good Wife (2013-2014), Madam Secretary (2014), Will & Grace (2018-2019). He has received two Primetime Emmy Award nominations for his specials, Child in his 50's (2001), and Unfair and Unbalanced (2010). He was profiled in the Starz documentary Robert Klein Still Can't Stop His Leg (2016).