Waikato Tainui, Waikato or Tainui is a group of Māori iwi based in the Waikato Region, in the western central region of New Zealand's North Island. It is part of the larger Tainui confederation of Polynesian settlers who arrived to New Zealand on the Tainui waka. The tribe is named after the Waikato River, which plays a large part in its history and culture.