| Ihaia Tainui | |
| Death Place: | Arahura Pā, Westland, New Zealand |
| Relations: | Tuhuru Kokare (grandfather) |
| Constituency Mp: | Southern Maori |
| Parliament: | New Zealand |
| Term Start: | 1879 |
| Term End: | 1881 |
| Predecessor: | Hōri Kerei Taiaroa |
| Successor: | Hōri Kerei Taiaroa |
Ihaia Tainui (died 19 October 1885) was a Māori member of the New Zealand parliament.
He was the son of Wereta Tainui and grandson of Tuhuru Kokare, both chiefs of the Ngāi Tahu hapū (sub-tribe) Ngāti Waewae.[1]
He represented the electorate of Southern Maori from 1879 (after Hōri Kerei Taiaroa was disqualified) to 1881, when he resigned and Hori Taiaroa resumed the electorate.[2]
Tainui committed suicide by hanging on 19 October 1885 in the whare rūnanga at Arahura Pā, north of Hokitika.[3] [4]