AFF, Aff or aff may refer to:
Aviation
- Accelerated freefall, a method of skydiving training
- Automated Flight Following (AFF), a US Department of Agriculture system to track firefighting aircraft
- IATA airport code for United States Air Force Academy Airfield in Colorado Springs, State of Colorado, US
Organizations
- Afghanistan Football Federation, the governing body of football in Afghanistan
- Afghanistan Freedom Front, an anti-Taliban militant group
- Animal Farm Foundation, an advocacy group for pit bulls and against breed-specific legislation
- Arab Film Festival, a California nonprofit that hosts the largest Arab film festival in the US
- Armed Forces Foundation, a military non-profit support group
- ASEAN Football Federation, a subset of nations within the Asian Football Confederation from Southeast Asia
- Aspies For Freedom, a group advocating autism rights
- Austin Film Festival, a film festival in Austin, Texas
- Australian Fencing Federation, the governing body of the Olympic sport of fencing in Australia
Transport
- Affluence stop, MTR station code "AFF"
Other uses
- Adult FriendFinder, a commercial dating website
- Advanced Fighting Fantasy, a British fantasy tabletop roleplaying game
- , an open and extensible file format to store disk images and associated metadata
- Advance-fee fraud, a confidence trick in which the target is persuaded to advance relatively small sums of money in the hope of realizing a much larger gain
- aff., an abbreviation for affinis in biological open nomenclature
- Affine group, <math>\operatorname{Aff}</math> is used to represent the group of affine transformations on a space
- Aff (river), in western France
- A Fine Frenzy, a singer