| Pat Hannivan | |
| Position: | Outfielder/Second baseman |
| Bats: | Unknown |
| Throws: | Left |
| Birth Date: | 20 April 1866 |
| Birth Place: | Halifax, Nova Scotia |
| Death Place: | Springfield, Massachusetts |
| Debutleague: | MLB |
| Debutdate: | April 29 |
| Debutyear: | 1897 |
| Debutteam: | Brooklyn Bridegrooms |
| Finalleague: | MLB |
| Finaldate: | October 2 |
| Finalyear: | 1897 |
| Finalteam: | Brooklyn Bridegrooms |
| Statleague: | MLB |
| Stat1label: | Batting average |
| Stat1value: | .250 |
| Stat2label: | Home runs |
| Stat2value: | 0 |
| Stat3label: | Runs batted in |
| Stat3value: | 2 |
| Teams: |
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Patrick James Hannivan (April 20, 1866 – November 5, 1908) was a Canadian professional baseball player. He played part of the 1897 season in Major League Baseball for the Brooklyn Bridegrooms. He appeared in three games as an outfielder and two games as a second baseman.