Ass may refer to:

• Ass (animal) or donkey
• Asinus
• Buttocks, in colloquial usage
• Ass (album), by Badfinger
• ASS (car), a French car made from 1919 to 1920
• ASS (gene), a human gene that encodes for the enzyme argininosuccinate synthetase
• Advanced SubStation Alpha, a subtitles editor in computing
• American Sociological Association, formerly the American Sociological Society
• Arse in American English
• Angle-Side-Side, a faulty proof in mathematics

See also

• AS (disambiguation)
• Asshole (disambiguation)
• Asso