Auto-Cycle Union
| Sport | Motorcycling | 
|---|---|
| Founded | 1903 | 
| Affiliation | Fédération Internationale de Motocyclisme | 
| Affiliation date | 1904 | 
| Official website | |
| www | |
The Auto-Cycle Union (ACU) is the governing body of motorcycle sport in the British Isles, including the Channel Islands and the Isle of Man, excluding Northern Ireland and the Republic of Ireland.