| Abbreviation | Definition |
|---|---|
| AAF | Alliance of American Football |
| AAFA | American Amateur Football Association |
| AAFAU | Asociación Argentina de Fútbol Australiano (Portugese: Argentine Australian Football Association) |
| AAFC | All America Football Conference |
| AAFC | All American Football Conference |
| AAFC | Association of Australian Football Clubs |
| AAFL | All American Football League |
| AAFL | Auckland Australian Football League |
| ABC | Anyone But Collingwood |
| ABCF | AIIMS Bhopal Club de Football |
| ABFA | African Brothers Football Academy |
| ABFA | Antigua and Barbuda Football Association |
| ACFC | All Canadian Football Club |
| ACFC | Angouleme Charente Football Club |
| ACFC | Aston Clinton Football Club |
| ACFC | Atherton Colleries Football Club |
| ACFC | Atlantic Central Football Conference |
| ACFF | Association des Clubs Francophones de Football |
| ACFG | AC Football Group |
| ACFL | Action College Football League |