John Joseph Hannifin (February 25, 1883 – October 27, 1945) was an American Major League Baseball infielder. He played for the Philadelphia Athletics during the 1906 season, the New York Giants from 1906 to 1908, and the Boston Doves during the 1908 season.
Jack Hannifin
| Given name: | John Joseph Hannifin |
| Nicknames: | None |
| Primary Pos: | Thirdbase |
| Hght/Wght: | 5'11" / 167 lbs |
| Bats/Throws: | R / R |
| Born: | Feb 25, 1883 in Holyoke, MA |
| Died: | Oct 27, 1945 in Northampton, MA (62 years old) |
| Debut: | Apr 19, 1906 |