Riwai Te Ahu (c1821–1866) was a notable New Zealand teacher and missionary. Of Māori descent, he identified with the Ngāti Hinerangi and Ngāti Awa iwi (tribe). He was born in Waitara, Taranaki, New Zealand. He was the son of Tuhoe of Waiongana and Waipuia of Waitara. In 1840 he was baptised by the Rev. Octavius Hadfield at the Waikanae Mission of the Church Missionary Society (CMS). From about 1840 to 1854 he was a catechist and teacher at the CMS mission at Waikanae. He worked with Hadfield to establish schools among the Māori people living in Queen Charlotte Sound, including at Okukari Bay.