Jack O'Brien boxer
- bouts
- 2
- won
- 1
- lost
- 1
- draw
- 0
- Status
- inactive
- Division
- bantamweight
- Debut
- 1920-09-06
- Height
- -
- Reach
- -
- Age
- -
- Born
- -
- Death
- -
- Nationality
- USA
| Date | Opponent | Last Opponents' Results | Place | Result |
|---|---|---|---|---|
| 1922-03-14 | Charlie Young Kivi | DLLLWL | Eagles' Hall, Lorain | WIN |
| 1922-03-01 | Charlie Young Kivi | DDLLLW | Lorain | WIN |
| 1922-02-28 | Mike Moran | WLWLWW | Oak Hill Auditorium, Youngstown | LOST |
| 1922-02-27 | Eddie McGovern | debut | Armory, Sandusky | WIN Technical knockout |
| 1921-08-30 | Johnny McCoy | WWWDLL | Cleveland | LOST |
| 1921-05-26 | Al Corbett | WWWWWW | Alliance | LOST KO |
| 1921-04-08 | Al Ziemer | WLWWW | Troop A Armory, Cleveland | LOST |
| 1921-03-10 | Tommy O'Boyle | WLWLLW | Cleveland | DRAW |
| 1921-01-24 | Young Conway | debut | Marotta A.C., Cleveland | WIN |
| 1920-12-27 | Young Harkness | debut | Cleveland | WIN |
| 1920-09-06 | Charlie Young Kivi | debut | Mansfield | WIN |