- Ab (Semitic), a common part of Arabic-derived names, meaning "father of" in Arabic.
- A volcano on the island of Honshū in Japan.
- Mount Abu, the highest mountain in the Indian state of Rajasthan.
- Abu, Yamaguchi, a town in Japan.
- (mythology) A minor god of vegetation in Sumerian mythology.
- The fifth month of the Babylonian calendar.
- The ancient Egyptian name for the city of Elephantine, near modern day Aswan.
- A language of Papua New Guinea which is not related to Abau and nor to Abui.