Jack O'Brien boxer
- bouts
- 5
- won
- 0
- lost
- 4
- draw
- 1
- Status
- inactive
- Division
- bantamweight
- Debut
- 1930-05-09
- Height
- -
- Reach
- -
- Age
- -
- Born
- -
- Death
- -
- Nationality
- USA
| Date | Opponent | Last Opponents' Results | Place | Result |
|---|---|---|---|---|
| 1931-11-10 | Gene Dundee | WLW | Llewellyn Hall, Orange | LOST Points |
| 1931-02-28 | Carmine Nacchio | DDWWWW | 14th Infantry Armory, Brooklyn | LOST KO |
| 1930-11-08 | Carmine Nacchio | WW | 14th Regiment Armory, Brooklyn | LOST Points |
| 1930-09-18 | Joe Reno | debut | Fort Hamilton Arena, Brooklyn | LOST KO |
| 1930-05-09 | Baby Jacobs | L | Oasis, Portsmouth | DRAW Points |