may refer to the following:
In medicine and science:
In popular culture:
- Fatty Bear, a fictional teddy bear from game developer Humongous.
- Fatty Finn, an Australian film.
- Fatty Koo, an American band.
- Fatty McButterpants, an episode of The King of Queens.
- I, Fatty, an American novel by Jerry Stahl.
- Roscoe Arbuckle, a comedian known as Fatty Arbuckle.
- Fredegar Bolger, called "Fatty", character in J. R. R. Tolkien's The Lord of the Rings.
- Fatty Lumpkin, a pony from The Lord of the Rings.
- The slang term for an oversized cannabis or hashish joint or blunt.
- A derogatory term for someone who is obese.
- A character in "The Bash Street Kids" in the UK's Beano comic.
- FAT - disambiguation page