Rahiri is a semi-mythical ancestor of the Māori people in New Zealand.
Rahiri lived somewhere within the period 1475-1585, based on whakapapa (genealogical) calculations. He traced descent from Kupe of the Matawhaorua canoe and Nukutawhiti of the enlarged and renamed Ngātokimatawhaorua canoe.
Rahiri is the eponymous tupuna (ancestor) of Ngapuhi, today the largest iwi (tribal nation confederation) in New Zealand. His significance for Ngapuhi is that all the chiefly lines of descent in Ngapuhi trace descent through him. As the saying goes:
"Mehemea he uri koe no Ngapuhi, kihai e koe i heke ia Rahiri, he hoiho ke koe!" ("If you are Ngapuhi and do not descend from Rahiri, then you are a horse!")
His first wife was Ahuaiti. From this union came the first-born son, Uenuku. Uenuku was also known as Uenukukuare (Uenuku the Ignorant): while still a young boy, together with his mother Ahuaiti, he was cast out by Rahiri and it was only when he was a young man that he was reconciled with his father Rahiri. Ahuaiti had allegedly given her visiting brothers some of Rahiri's best fern root, contrary to his instructions to her. This was the reason for her exile. Rahiri's second wife was Whakaruru and from this union came Kaharau who, together with Uenuku founded the military might of Ngapuhi.
Upon reconciliation, the then territories of Ngapuhi were divided up by Rahiri on the basis of the flight and landing place of the kite, Tuhoronuku. Uenuku and Kaharau further consolidated connection through marriage of children.
Rahiri had other wives, two being Moetonga and Paru, descendents of these wives respectively settling the west and east coasts within Ngapuhi-controlled territories, creating hapū in those places.