BUFF may refer to:
- Abbr. - Big Useless Fat F*cker - see also mooch, a classic civilian version of a BUFF is John Prescott.
- A nickname for the American B-52G & H bombers as used by the USAF.
- A nickname for the former Secretary of State for Defence, also known as TCH
- A state of undress as often used by "geezers" ie, I have no clothes on, I'm in the buff! The preferred state of dress for the Royal Marines in either combat or recreation.