| Competition: | Irish League |
| Season: | 1899–1900 |
| Winners: | Celtic 1st Irish title |
| Matches: | 27 |
| Total Goals: | 95 |
| Prevseason: | 1898–99 |
| Nextseason: | 1900–01 |
The 1899–1900 Irish League was the 10th edition of the Irish League, the highest level of league competition in Irish football.
The league comprised 6 teams, and Belfast Celtic won the championship.