Lois Maureen Stapleton (born June 21, 1925 in Troy, New York) in an American theater and film actress.

Stapleton began acting in theater after finishing high school, and rapidly gained respect as both a dramatic and comedic actress. She has said that it was her infatuation with the actor Joel McCrea that led her into acting, and she made her Broadway debut in Burgess Meredith's production of The Playboy of the Western World in 1946.

Stepping in as a replacement for Anna Magnani, Stapleton won a Tony Award for her role in Tennessee Williams' The Rose Tattoo in 1951. She played in other Williams' productions Twenty-Seven Wagons Full of Cotton and Orpheus Descending, as well as Lillian Hellman's Toys in the Attic. She won a second Tony Award for Neil Simon's The Gingerbread Lady in 1971.

Her film career also brought her immediate success, with her debut in Lonelyhearts (1958) earning her a nomination for an Academy Award for Best Supporting Actress. She was nominated again for Airport and Interiors (1978), and won for Reds (1981). Her more recent appearances include Cocoon and Cocoon: The Return (1985 and 1988).

She is of no relation to actress Jean Stapleton.