Ainu (Ainu: , Aynu itak; Japanese: Ainu-go; Cyrillic alphabet: ) is one of the Ainu languages, spoken by members of the Ainu ethnic group on the northern Japanese island of Hokkaidō.
Until the twentieth century, Ainu languages were also spoken throughout the southern half of the island of Sakhalin and by small numbers of people in the Kuril Islands. All but the Hokkaidō language are extinct, with the last speaker of Sakhalin Ainu having died in 1994; and Hokkaidō Ainu is moribund, though there are ongoing attempts to revive it.
Ainu has no generally accepted genealogical relationship to any other language family. For the most frequent proposals, see Ainu languages.