Ngātiwai or Ngāti Wai is a Māori iwi of the east coast of the Northland Region of New Zealand.

[1] Notable descendants of Ngātiwai include brothers Jim, Ian and Winston Peters, artist Shona Rapira Davies, and writer Paula Morris.

[citation needed] Following a battle with Ngāpuhi at their pā at Mimiwhāngata, Ngāti Manaia fled out to sea, along the eastern coast, and on to the offshore islands.

[citation needed] Known for their ocean traditions and customs and coastal raiding, Ngātiwai ("descendants of the sea") were often accompanied by a guardian sea-hawk or Tūkaiaia, whereby other tribes would be warned that Ngātiwai were on the move – either at sea or on land.

[2][3] In April 2006, Ngātiwai sued the Department of Conservation over its handling of consultation issues in Northland regarding a marine reserve.