Jack O'Brien boxer
- bouts
- 21
- won
- 3
- lost
- 18
- draw
- 0
- Status
- inactive
- Division
- lightweight
- Debut
- 1917-01-25
- Height
- -
- Reach
- -
- Age
- -
- Born
- -
- Death
- -
- Nationality
- USA
| Date | Opponent | Last Opponents' Results | Place | Result |
|---|---|---|---|---|
| 1926-05-28 | Wally Theroux | WWLDLW | Pine Street Arena, Nashua | LOST Points |
| 1925-02-05 | Bert Jones | LLLLLW | Crescent Rink, Lowell | LOST Points |
| 1924-12-18 | Larry Robinson | WWWWLL | Crescent Rink, Lowell | LOST Points |
| 1924-12-11 | Tommy Leonard | WWWWLL | Crescent Rink, Lowell | LOST Points |
| 1924-10-02 | Leo Desrosier | DWWWWW | Crescent Rink, Lowell | LOST Points |
| 1924-09-18 | Nick Madonna | LWWWWW | Crescent Rink, Lowell | LOST Points |
| 1924-06-05 | Nick Madonna | WWWLWW | Crescent Rink, Lowell | LOST Points |
| 1924-05-02 | Wally Theroux | LDWWWW | Nashua Theatre, Nashua | LOST Points |
| 1924-03-06 | Wally Theroux | DDLWLD | Crescent Rink, Lowell | LOST Points |
| 1924-02-14 | Nick Madonna | WLLWWW | Crescent Rink, Lowell | WIN Points |
| 1923-11-26 | Willie Nelson | WLWL | Casino Hall, Lynn | LOST Points |
| 1923-10-29 | Leo Derosiers | debut | O'Donnell Hall, Nashua | LOST Points |
| 1923-03-15 | Frankie Christo | WWLWWL | Crescent Rink, Lowell | WIN Technical knockout |
| 1923-02-22 | Frankie Buff | WWWWWW | Crescent Rink, Lowell | LOST Points |
| 1923-02-15 | Frankie Buff | LWWWWW | Crescent Rink, Lowell | LOST Points |
| 1923-02-06 | Buddy Dolan | LLLWL | City Hall, Lawrence | LOST Points |
| 1923-02-01 | Tommy Dalton | LWLLL | Crescent Rink, Lowell | WIN Points |
| 1922-03-09 | Martin Flaherty Jr. | debut | Crescent Rink, Lowell | LOST Points |
| 1921-04-14 | Henry Kenoyer | LLWDLW | Olympia Theatre, Nashua | LOST Points |
| 1919-02-27 | Frank Mollins | WWWD | Crescent Rink, Lowell | LOST KO |
| 1917-01-25 | Johnny Hill | debut | Unity Cycle Club, Lawrence | LOST KO |