George O'Brien was an American actor, popular during the silent film era and into the talkie era of the 1930s, best known today as the lead actor in F. W. Murnau's 1927 film .
Born in San Francisco, California, O'Brien was the oldest son of Daniel J. and Margaret L. O'Brien; O'Brien's father later became the Chief of Police for the City of San Francisco. After his retirement from that office, Dan was the Director of Penology for the State of California.
In 1917 O'Brien enlisted in the United States Navy to fight in World War I, serving on a Submarine chaser. He volunteered to act as a stretcher bearer for wounded Marines and was decorated for bravery. Right after the war O'Brien became Light Heavyweight champion of the Pacific Fleet.
O'Brien came to Hollywood in his early twenties hoping to become a cameraman and did work as an assistant cameraman for a while, for both Tom Mix and Buck Jones. He began his acting career in bit parts and as a stuntman. One of his earliest roles was in the 1922 George Melford-directed drama Moran of the Lady Letty, most notable for starring Rudolph Valentino. In 1924 O'Brien received his first starring role in the drama The Man Who Came Back opposite the English actress Dorothy Mackaill. That same year he was chosen by the famed movie director John Ford to star in The Iron Horse opposite actress Madge Bellamy. The film was an immense success at the box-office and O'Brien made nine more films for Ford. In 1927 he starred in the F. W. Murnau-directed Sunrise opposite Janet Gaynor, which won three Academy Awards.