Walter Matthau (born Walter John Matthow; October 1, 1920 – July 1, 2000) was an American actor, comedian and film director.

He is best known for his film roles in A Face in the Crowd (1957), King Creole (1958) and as a coach of a hapless little league team in the baseball comedy The Bad News Bears (1976). He also starred in 10 films alongside Jack Lemmon, including The Odd Couple (1968), The Front Page (1974) and Grumpy Old Men (1993). Matthau won the Academy Award for Best Supporting Actor for his performance in the Billy Wilder film The Fortune Cookie (1966). Matthau is also known for his performances in Stanley Donen's romance Charade (1963), Gene Kelly's musical Hello, Dolly! (1969), Elaine May's screwball comedy A New Leaf (1971) and Herbert Ross' ensemble comedy California Suite (1978). He also starred in Plaza Suite, Kotch (both 1971), Charley Varrick (1973), The Sunshine Boys (1975), and Hopscotch (1980).

On Broadway, Matthau originated the role of Oscar Madison in The Odd Couple by playwright Neil Simon, for which he received a Tony Award for Best Actor in a Play in 1965, his second after A Shot in the Dark in 1962. Matthau also received two British Academy Film Awards and a Golden Globe Award. In 1963, he received a Primetime Emmy Award nomination for his performance in The DuPont Show of the Week. In 1982, he received a star on the Hollywood Walk of Fame.