Iaai (Iaai pronunciation: [jaːi]) is a language of Ouvéa Island (New Caledonia). It shares the island of Ouvéa with Fagauvea, a Polynesian outlier language.

Iaai is the sixth-most-spoken language of New Caledonia, with 4,078 speakers as of 2009. It is taught in schools in an effort to preserve it.

The language has been studied by linguists Françoise Ozanne-Rivierre and Anne-Laure Dotte.

Iaai is remarkable for its large inventory of unusual phonemes, in particular its consonants, with a rich variety of voiceless nasals and approximants.

Iaai has ten vowel qualities, all of which may occur long and short. There is little difference in quality depending on length.

Iaai constitutes one of the few cases of front rounded vowels attested outside of their geographic stronghold in Eurasia, even if other cases have since been reported in the Oceanic family.

The vowel /ø øː/ is only known to occur in six words. In all of these but /ɲ̊øːk/ "dedicate", it appears between a labial (b, m) and velar (k, ŋ) consonant.

After the non-labiovelarized labial consonants and the vowel /y yː/, the vowel /ɔ ɔː/ is pronounced [œ œː].