| Competition: | Irish League |
| Season: | 1909–10 |
| Winners: | Cliftonville 2nd Irish title |
| Matches: | 56 |
| Total Goals: | 160 |
| Prevseason: | 1908–09 |
| Nextseason: | 1910–11 |
The 1909–10 Irish League was the 20th edition of the Irish League, the highest level of league competition in Irish football.
The league comprised 8 teams, and Cliftonville won the championship.