New York Jack O'Brien boxer
- bouts
- 40
- won
- 14
- lost
- 10
- draw
- 14
- Status
- inactive
- Division
- lightweight
- Debut
- 1897-05-23
- Height
- 5′ 6″/168cm
- Reach
- -
- Age
- -
- Born
- 1878-01-01
- Death
- -
- Nationality
- Canada
| Date | Opponent | Last Opponents' Results | Place | Result |
|---|---|---|---|---|
| 1906-03-19 | Howard Smith | LWD | Marlborough A.C., New York | WIN |
| 1905-02-11 | Jack Cardiff | LLLWLD | Manayunk A.C., Philadelphia | LOST KO |
| 1904-06-11 | Tom Massey | debut | Mira Monte Hall, Montecito | NC No Contest |
| 1902-09-12 | Frank Christy | debut | Pastime A.C., Sacramento | LOST Points |
| 1902-04-15 | Kid Williams | LWLDW | Stockton | LOST Points |
| 1902-03-21 | Rufe Turner | WWWDLW | Woodward's Pavilion, San Francisco | LOST Technical knockout |
| 1902-01-16 | George Young Gibbs | WWWWLW | Exposition Building, Oakland | WIN Points |
| 1901-11-26 | Perry Queenan | DDLDWL | Sacramento | DRAW Points |
| 1901-10-11 | Rufe Turner | DWWWWD | Stockton | WIN Points |
| 1901-06-28 | Buddy King | WLWWDW | Colorado A.A., Denver | WIN Points |
| 1900-10-26 | Wilmington Jack Daly | WDDLLW | Auditorium, Waterbury | DRAW Points |
| 1900-10-04 | Tim Kearns | WWDWWW | Nutmeg A.C., Hartford | WIN Technical knockout |
| 1900-07-30 | George 'Elbows' McFadden | WWWWDW | Madison Square Garden, New York | LOST Technical knockout |
| 1900-06-16 | Tim Kearns | LWWWDW | Seaside A.C., Coney Island | LOST |
| 1900-04-30 | George 'Elbows' McFadden | DWWWWW | Broadway A.C., New York | DRAW Points |
| 1899-12-04 | Frank Erne | DWDWWW | Coney Island A.C., Brooklyn | DRAW Points |
| 1899-09-29 | Tim Kearns | LWWWWW | Broadway A.C., Brooklyn | WIN KO |
| 1899-08-21 | Jack Downey | DWDLLW | Coney Island A.C., Brooklyn | WIN KO |
| 1899-07-07 | Dal Hawkins | DWLWDL | Broadway A.C., Brooklyn | WIN Points |
| 1899-05-29 | Martin Flaherty | DWWDWD | Lenox A.C., New York | WIN Points |
| 1899-04-19 | Dave Sullivan | WWLLDD | Coliseum, Hartford | DRAW Points |
| 1899-04-07 | Jack Downey | WLDDWD | Broadway A.C., Brooklyn | WIN |
| 1899-03-04 | Marty McCue | LWDDDL | Greenwood A.C., Brooklyn | LOST Points |
| 1899-02-18 | Billy Whistler | DWDWDD | Greenwood A.C., Brooklyn | DRAW Points |
| 1899-02-13 | Oscar Gardner | DLWWDW | Youngstown | WIN Points |
| 1898-12-03 | Billy Whistler | DDWDW | Greenwood A.C., Brooklyn | DRAW Points |
| 1898-10-22 | Marty McCue | LWWWWD | Pelican A.C., Brooklyn | DRAW Points |
| 1898-09-22 | Joe Cain | DWDDWL | Greenwood A.C., Brooklyn | WIN Technical knockout |
| 1898-07-30 | Jim Barron | WDWDD | Sydney | DRAW Points |
| 1898-02-24 | Yock Henniger | DDLWLL | Horizon A.C., Bridgeport | DRAW Points |
| 1898-01-20 | Yock Henniger | WDDLWL | Auditorium, Waterbury | WIN Points |
| 1897-12-02 | Frank Patterson | DDWDWW | Park City Theater, Bridgeport | DRAW Points |
| 1897-11-13 | Oscar Gardner | WDDWWW | Polo A.C., New York | LOST Points |
| 1897-10-28 | Joe Cain | DWWD | Active A.C., Maspeth, Queens | WIN KO |
| 1897-10-18 | Martin Judge | LLDWLL | Quaker City A.C., Philadelphia | NC No Contest |
| 1897-10-04 | Mark Kerwin | W | New Kensington | DRAW Points |
| 1897-08-30 | Oscar Gardner | WWDDWD | Greenpoint S.C., Brooklyn | DRAW Points |
| 1897-08-12 | George Johnson | LWLLDL | City Hall, Waterbury | WIN Points |
| 1897-07-19 | Oscar Gardner | WWWDDW | Albany | DRAW Points |
| 1897-05-26 | Mike Sears | WWDDWW | Palace A.C., New York | LOST Points |
| 1897-05-23 | Jack Delaney | DWDWWL | Polo A.C., New York | LOST Points |