| Sport | Baseball |
|---|---|
| Founded | 1884 |
| Ceased | 1884 |
| President | Henry Lucas |
| No. of teams | 12 |
| Country | United States |
| Last champion(s) | St. Louis Maroons (1884) |
The Union Association was an American professional baseball league which competed with Major League Baseball, lasting for just the 1884 season. St. Louis won the pennant and joined the National League the following season.
Seven of the twelve teams who were in the Association at some point during the season did not play a full schedule: four teams folded during the season and were replaced, while Chicago moved to Pittsburgh in late August.