Nainativu (Tamil: நயினாதீவு Nainatheevu, Sinhala: නාගදීපය Nagadeepa),[1][2] is a small but notable island off the coast of Jaffna Peninsula in the Northern Province, Sri Lanka.

The Manimekhalai and the Mahavamsa both describe Buddha settling a dispute between two Naga princes over a gem set throne seat on an island known as Manipallavam or Nagadeepa, identified as Nainativu by several scholars.

[9] The Tamil language inscription of the Nainativu Hindu temple by Parâkramabâhu I of the 12th century CE states that foreigners landing at new ports must meet at Kayts and they must be protected, and if ships to the islet carrying elephants and horses get shipwrecked, a fourth of the cargo must go to the treasury.

[14][15] They also likely spoke Prakrit, a language of the school of Amaravathi village, Guntur district with which the early Tamils of Jaffna had strong cultural relations during the classical period.

The findings include Nāka idols and suggest that serpent worship was widely practised in the Dravidian regions of India and Sri Lanka during the megalithic period.

The name Nāka was either a corrupted version of the word Nayinaar or may have been applied to this community due to their head covering being the shape of a hydra-headed cobra in reverence to their serpentine deities.

[21] Some scholars derives the origin of the Pallava dynasty of Tamilakam from an marriage alliance of the Cholas and the Naga from Jaffna Peninsula.