About Pat O'Brien (actor)
William Joseph Patrick O'Brien was an American film actor with more than 100 screen credits. Of Irish descent, he often played Irish and Irish-American characters and was referred to as "Hollywood's Irishman in Residence" in the press. One of the best-known screen actors of the 1930s and 1940s, he played priests, cops, military figures, pilots, and reporters. He is especially well-remembered for his roles in Knute Rockne, All American (1940), Angels with Dirty Faces (1938), and Some Like It Hot (1959). He was frequently paired onscreen with Hollywood star and close friend James Cagney. O'Brien also appeared on stage and television. O'Brien's first Warner Bros. movie was Bureau of Missing Persons (1933), starring Bette Davis. Here Comes the Navy (1934) was O'Brien's first film with James Cagney, also under contract to Warners. He was with Blondell in Off the Record (1939) and The Kid from Kokomo (1939), and co-starred with Gale Page in Indianapolis Speedway (1939).
Biography source: Wikipedia. The profile adds birthday-specific historical context from the Celebs Birthday Today editorial database.