Ilangai is the Tamil name (இலங்கை; written in Tamil script) for the island of Sri Lanka.
Ilangai may also refer to:
Ilanga impolita, a species of gastropod Ilanga illustris, a species of gastropod Ilanga, a genus of gastropods Ilanga incisura, a species of gastropod Ilankai Tamil Arasu Kachchi, a nationalist party from the Tamil part of Sri Lanka