Curiosidades

The 1926 Standard Casting Directory says Billy is 5 years old.

Brother of Gene O'Brien Eugene O'Brien.

8/28/1944 Culver City Evening Star News: "Captain William O'Brien Lost in Pacific" news article states that Captain William S. O'Brien Culver City Ace in the South Pacific theatre of war has been missing in action since August 4. He has shot down a number of Japanese planes and latest reports indicate that the mission on which he was missing was somewhere in the New Guinea area.

As an adult Billy started going by the stage name Stephen O'Brien as listed in the 1939 casting directory "The Players Directory" (No. 16).