Tainui has taken full control of the company operating Novotel Tainui Hotel and Ibis Tainui Hotel in central Hamilton.
The tribe's commercial division, Tainui Group Holdings, has bought the remaining 17 percent stake in the business from Accor .
Accor has won a contract to manage the hotels for a further 25 years.
The purchase completes the iwi's buy-out of the overarching businesses, Hamilton Riverview Hotel Limited.
Last year the tribe bought a 41 percent stake that was held by Hamilton City Council.