Jack O'Brien boxer
- bouts
- 5
- won
- 1
- lost
- 1
- draw
- 2
- Status
- inactive
- Division
- -
- Debut
- 1909-02-16
- Height
- -
- Reach
- -
- Age
- -
- Born
- -
- Death
- -
- Nationality
- USA
| Date | Opponent | Last Opponents' Results | Place | Result |
|---|---|---|---|---|
| 1914-12-10 | Buddy Dolan | D | Unity Cycle Club, Lawrence | LOST KO |
| 1910-03-01 | Connie Barnes | W | Associate Hall, Lowell | DRAW Points |
| 1909-03-25 | Billy Mulvey | debut | Conlon Building, Lowell | DRAW Points |
| 1909-02-22 | Frank Kennedy | debut | Conlon Building, Lowell | NC No Contest |
| 1909-02-16 | Young Sullivan | W | Conlon Building, Lowell | WIN Points |