Brooks was born Ruben Sax to Russian Jewish immigrants in Philadelphia, Pennsylvania and graduated from West Philadelphia High School, and later Temple University. He was a sports reporter at several newspapers (the Atlantic City Press Union, the Philadelphia Record and the New York World-Telegram), then moved into radio at WNEW in New York. He served at the NBC network as a staff writer in the 1930s before directing for the stage at the Mill Pond Theatre in New York. He then spent several years in Hollywood as a staff writer for low-budget pictures and serials before serving in the U.S. Marines during World War II.

His second published novel was Splinters in 1941, but his 1945 novel, The Brick Foxhole, was a larger success - it is the story of a group of Marines who pick up and then murder a homosexual man, and the novel is a stinging indictment of intolerance. The book was made into a movie in 1947 as Crossfire, though the intolerance was switched from homophobia to anti-Jewishness to please studio executives and 1940s audiences (Brooks received credit for the book on which the movie is based, but was contractually barred from actually working on the screenplay).

In the 1940s he wrote the screenplays for the critically acclaimed Key Largo and Brute Force, both suspenseful examples of film noir. He also co-wrote Storm Warning, an anti-Klan melodrama with film-noir overtones, in conjunction with Daniel Fuchs. In 1950 he directed his film Crisis, which gave a much darker role to the actor Cary Grant than he had previously attempted. He won his only Oscar in 1960 for his screenplay for Elmer Gantry, although he was nominated for the films Blackboard Jungle (1955), Cat on a Hot Tin Roof (1958), The Professionals (1966), and In Cold Blood (1967).

Other notable films directed by Brooks include The Brothers Karamazov starring Yul Brynner, Lord Jim starring Peter O'Toole, The Last Time I Saw Paris with Elizabeth Taylor -- adapting, in their turn, Dostoyevsky, Joseph Conrad, and F. Scott Fitzgerald. His last significant project was the controversial Looking for Mr. Goodbar.

In 1960 he married the British actress Jean Simmons, whom he directed in Elmer Gantry, and they had one daughter. They divorced in 1977.

He became part of Hugh Hefner's family, and part of Hefner's feudal mansion, where he was observed by the satirist Clive James: "Hefner's estate teemed with voluptuous young women and the dining-room where free hamburgers were available 24 hours a day was impressively populated with Hollywood male notables. But it was sadly apparent that most of them were superannuated lechers. The film director Richard Brooks was typical. He hadn't directed a film in decades and one of the reasons was that he had been here, chomping the free hamburgers, while he eyed the women. He was in Hef's hamburger heaven, sizing up the poontang on his way to a final resting place in Hillside Memorial Park."

Brooks died from congestive heart failure in 1992 in Beverly Hills, California and was interred in the Hillside Memorial Park Cemetery in Culver City, California. For his contribution to the motion picture industry, Brooks has a star on the Hollywood Walk of Fame at 6422 Hollywood Blvd.