Jack Brennan boxer
- bouts
- 11
- won
- 4
- lost
- 6
- draw
- 1
- Status
- inactive
- Division
- welterweight
- Debut
- 1919-07-04
- Height
- -
- Reach
- -
- Age
- -
- Born
- -
- Death
- -
- Nationality
- USA
| Date | Opponent | Last Opponents' Results | Place | Result |
|---|---|---|---|---|
| 1922-05-19 | Cyclone Gavvy | DDWWDW | Newman A.C., Newman | LOST KO |
| 1920-05-20 | George Shade | WWWWL | Hollister | LOST Technical knockout |
| 1920-05-13 | Steve Dalton | DWWWDL | Coliseum, San Francisco | LOST Technical knockout |
| 1920-04-06 | Johnny Vierra | WLDDWW | Floral A.C., San Mateo | LOST Points |
| 1920-03-09 | Tom Tracey | W | Floral A.C., San Mateo | WIN Points |
| 1919-11-21 | Joe Stanton | LDWLDD | Dreamland Rink, San Francisco | LOST Points |
| 1919-10-03 | Jimmy Fortney | LDWWLD | Dreamland Rink, San Francisco | DRAW Points |
| 1919-09-01 | Joe Ferro | LLLDLL | Rodeo Arena, San Francisco | WIN Points |
| 1919-08-29 | Lee Harvey | debut | Dreamland Rink, San Francisco | WIN Points |
| 1919-08-15 | Joe Ferro | WLLLDL | Dreamland Rink, San Francisco | WIN Points |
| 1919-07-04 | Sammy Pelsinger | WLWDDL | Floral A.C., San Mateo | LOST Points |