Paul Michael Kelly was born on August 9,189 9, in Brooklyn, New York, to a Roman Catholic family of Irish descent. He was the ninth of ten children. His father, Michael, owned a bar called Kelly's Cafe, where Kelly made his Broadway debut at the age of 8 in "The Grand Army Man".
Kelly's early career began at Vitagraph Studios, where he appeared in one-reel silent films and was known as 'Chick Kelly, the Vitagraph Boy'. He transitioned into teen and young adult roles, alternating between theater and movie assignments. He was romantically paired with Mary Miles Minter in the silent classic "Anne of Green Gables" (1919) and the success of that film moved him into even higher contention.
Kelly's personal life was marked by a tumultuous affair with actress Dorothy Mackaye, who was already married to Ziegfeld Follies song-and-dance man Ray Raymond. The couple's love affair led to a fatal fight between Kelly and Raymond, which resulted in Raymond's death. Kelly was convicted of manslaughter and sentenced to one to ten years in prison.
After his release from prison, Kelly returned to the stage and screen, appearing in numerous films and Broadway productions. He won a Tony Award for his performance in "Command Decision" and also won the Donaldson and Variety Critics awards. In the 1950s, he found plentiful work on standard TV drama.
Kelly suffered a heart attack in 1953 and was stricken again on Election Day, November 6, 1956, this time fatally, just after returning home from voting for Adlai Stevenson.