During the Depression, Sidney appeared in a string of films, often playing the girlfriend or the sister of a gangster. She appeared opposite such heavyweight screen idols as Spencer Tracy, Henry Fonda, Joel McCrea, Fredric March, George Raft (a frequent screen partner), and Cary Grant. Among her films from this period were: An American Tragedy, City Streets and Street Scene (all 1931), Alfred Hitchcock's Sabotage and Fritz Lang's Fury (both 1936), You Only Live Once, Dead End (both 1937) and The Trail of the Lonesome Pine, an early three-strip Technicolor film. It was during this period that she developed a reputation for being difficult to work with.
After what seemed to be a promising second phase of her career playing opposite the likes of James Cagney in films like Blood on the Sun (1945) with a considerably more glamorous screen persona, her career diminished somewhat during the 1940s. In 1949 exhibitors voted her "box office poison". In 1952, she played the role of Fantine in Les Misérables, and her performance was widely praised and allowed her opportunities to develop as a character actress.
Sidney appeared three times on CBS's Playhouse 90 anthology series. On May 16, 1957, she appeared as Lulu Morgan, mother of singer Helen Morgan in The Helen Morgan Story. In that same presentation Polly Bergen was nominated for an Emmy award for her portrayal of Helen Morgan. Four months later, Sidney joined Bergen, then twenty-seven, on the premiere of the short-lived NBC variety show, The Polly Bergen Show.
In 1973, Sidney received an Academy Award nomination for her supporting role in Summer Wishes, Winter Dreams. As an elderly woman Sidney continued to play supporting screen roles, and was identifiable by her husky voice, the result of a lifetime cigarette smoking habit. She was the formidable Miss Coral in the film version of I Never Promised You a Rose Garden and later was cast as Aidan Quinn's grandmother in the television production of An Early Frost for which she won a Golden Globe Award. She played Aunt Marion in Damien: Omen II and had key roles in Beetlejuice (directed by longtime Sidney fan Tim Burton), as Juno, for which she won a Saturn Award, and Used People (which co-starred Jessica Tandy, Marcello Mastroianni, Marcia Gay Harden, Kathy Bates and Shirley MacLaine). Her final role was in another film by Burton, Mars Attacks!, in which she played a senile grandmother whose beloved Slim Whitman records stop an alien invasion from Mars when played over a loudspeaker.
On television, she appeared in the first episode as the imperious mother of Gordon Jump in WKRP in Cincinnati; as the troubled grandmother of Melanie Mayron in the comedy-drama Thirtysomething and, finally, as the crotchety travel clerk on the short-lived late-1990s revival of Fantasy Island with Malcolm McDowell, Fyvush Finkel and Mädchen Amick. She also appeared in an episode of Dear John And an English teacher on an episode of My Three Sons (1969)
Sidney's Broadway theatre career spanned five decades, from her debut performance as a graduate of the Theatre Guild School in the June 1926 3-act fantasy Prunella to the Tennessee Williams play Vieux Carré in 1977. Additional credits include The Fourposter, Enter Laughing, and Barefoot in the Park.
In 1982, Sidney was awarded The George Eastman Award, given by George Eastman House for distinguished contribution to the art of film.
Tim Burton cast Sidney in his 1996 all-star comedy Mars Attacks!
Sylvia Sidney, born Sophia Kosow in The Bronx, was the daughter of Rebecca (née Saperstein), a Romanian Jew, and Victor Kosow, a Russian Jewish immigrant who worked as a clothing salesman. The area from which Victor Kosow came from is today in Belarus. Her parents divorced by 1915, and she was adopted by her stepfather, Sigmund Sidney, a dentist. Her mother became a dressmaker and renamed herself Beatrice Sidney. Now using the surname Sidney, she became an actress at the age of fifteen as a way of overcoming shyness. As a student of the Theater Guild's School for Acting, Sidney appeared in several of their productions during the 1920s and earned praise from theater critics. In 1926, she was seen by a Hollywood talent scout and made her first film appearance later that year.
As a single woman, Sidney was involved in an affair with B.P. Schulberg at Paramount Pictures. When Schulberg's previous mistress, Clara Bow, began experiencing personal problems in 1931, Sidney replaced her in City Streets.
Sidney was married three times. She first married publisher Bennett Cerf on 1 October 1935, but the couple were divorced shortly after on April 9, 1936. She then was married to actor and acting teacher Luther Adler from 1938 until 1947, by whom she had a son, Jacob (Jody) (October 22, 1939 – 1987), who died of Lou Gehrig's disease. During her marriage to Luther Adler she was a sister-in-law to acclaimed stage actress and drama teacher Stella Adler. On March 5, 1947, she married radio producer and announcer Carlton Alsop. They were divorced on March 22, 1951.
Sidney died from throat cancer in New York City a month before her 89th birthday, after a career spanning more than 70 years. She was cremated. She had no close family when she died. She bequeathed her black pug Malcolm to the National Arts Club, where the canine became a much loved mascot and noted attender of social events, celebrated in a short film by Carol Wilder.
She was skilled at needlepoint. She sold needlepoint kits featuring her designs, and she published two popular instruction books: Sylvia Sidney's Needlepoint Book (1968) and The Sylvia Sidney Question and Answer Book on Needlepoint (1975).
Sidney was also a staunch Republican and conservative.
Sidney has a star on the Hollywood Walk of Fame for her contribution to Motion Pictures at 6245 Hollywood Boulevard.