1909–10 Irish League
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 eight teams, and Cliftonville won the championship for the 2nd time.
Teams and locations
| Team | Town | Home Ground |
| Belfast Celtic | Belfast | Celtic Park |
| Bohemians | Dublin | Dalymount Park |
| Cliftonville | Belfast | Solitude |
| Derry Celtic | Derry | Brandywell |
| Distillery | Belfast | Grosvenor Park |
| Glentoran | Belfast | The Oval |
| Linfield | Belfast | Windsor Park |
| Shelbourne | Dublin | Sandymount Road |