A.I. is an abbreviation for:
- A type of sloth with three toes on each of its front feet (see also Unau, a two-toed sloth).
- The Irish-Celtic god of poetry, a member of the Tuatha de Danaan, also known as Aoi Mac Ollamain.
- In Norse mythology, the god Rig was travelling and happened upon a farm owned by Ai ("great grandfather") and his wife, Edda. They offered Rig shelter and a low quality meal. He slept between the pair at night; Edda gave birth nine months later to a son whom they named Thrall. Thrall grew up strong and ugly. He married Thir and had twelve sons and nine daughters. They became the serfs of Norse society.
- A place mentioned in the Bible, which is probably identical to the archaeological site of Et-Tell.
- Anguilla (Internet TLD)
- A.I, a 2001 film directed by Stephen Spielberg.