Donald David Dixon Ronald O’Connor (August 28, 1925 – September 27, 2003) was an American dancer, singer, and actor who came to fame in a series of movies in which he co-starred alternately with Gloria Jean, Peggy Ryan, and Francis the Talking Mule. He is best known today for his role as Gene Kelly's friend and colleague Cosmo Brown in Singin' in the Rain (1952).
Though he considered Danville, Illinois to be his home town, O’Connor was born in St. Elizabeth Hospital in Chicago, Illinois. His parents, Effie Irene (née Crane) and John Edward "Chuck" O'Connor, were vaudeville entertainers. His father's family was from County Cork, Ireland. When O'Connor was only a few years old, he and his sister Arlene were in a car crash outside a theater in Hartford, Connecticut; O'Connor survived, but his sister was killed. Several weeks later, his father died of a heart attack while dancing on stage in Brockton, Massachusetts. O'Connor at the time was being held in the arms of the theater manager Mr. Maurice Sims.
O'Connor began performing in movies in 1937. He appeared opposite Bing Crosby in Sing, You Sinners at age 12. Paramount Pictures used him in both A and B films, including Tom Sawyer, Detective and Beau Geste. In 1940, when he had outgrown child roles, he returned to vaudeville.
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