Sidney Kingsley was born in New York on 18th October, 1906. Educated at Cornell, he wrote one-act plays for the University's drama club.
Kingsley joined the the Group Theatre as an actor when it was was formed in New York by Harold Clurman and Lee Strasberg. Others involved in the group included Elia Kazan, Stella Adler, John Garfield, Paul Green, Howard Da Silva, Franchot Tone, John Randolph, Joseph Bromberg, Michael Gordon, Clifford Odets and Lee J. Cobb. Members of the group tended to hold left-wing political views and wanted to produce plays that dealt with important social issues.
In 1933 the Group Theatre performed Kingsley play, Men in White. The play, which was set in a hospital and dealt with moral issues such as abortion, was the Group's first box-office success. Highly acclaimed by the critics, Men in White won the Pulitzer Prizein 1934.
Kingsley's next play, Dead End (1935) dealt with the connections between slum housing and crime, was also highly successful. His next two productions, the anti-war play, Ten Million Ghosts (1936) and The World We Make (1939) were unpopular with the critics and and had only short-runs. However, his historical drama, The Patriots (1943), won the New York Drama Critics Circle Award.
Kingsley also wrote film scripts for Hollywood. This included Men in White (1934), Dead End (1937), Homecoming (1948) and the Detective Story (1951).
After the Second World War, most of the members of the Group Theatre were investigated by House of Un-American Activities Committee (HUAC). Some like Elia Kazan, Clifford Odets and Lee J. Cobb testified and named other members of left-wing groups. Those that refused to do this such as Stella Adler, John Garfield, Howard Da Silva, John Randolph, and Joseph Bromberg were blacklisted.
Kingsley, no longer able to write for Hollywood, concentrated on writing for the theatre. This included an adaptation of Arthur Koestler's novel, Darkness at Noon (1951), Lunatics and Lovers (1954) and Night Life (1962). Sidney Kingsley died on 18th October, 1995.