The official spelling of this region's name is changing to Manawatū-Whanganui.
The final decision was made by Land Information Minister Eugenie Sage, following an application to the New Zealand Geographic Board by Horizons Regional Council a year ago. The application was made after consulting iwi.
The change takes place from October 18.
Horizons is the council's trading name. Its official name will be Manawatū-Whanganui Regional Council.
The Whanganui spelling is consistent with the views of local tribes, a statement from the New Zealand Geographic Board said. It also matches the spelling of the Whanganui River, Whanganui National Park, Whanganui District and Whanganui town.
The accepted meaning for Whanganui is "the long wait", where "whanga" means "to wait". "Whanga" can also mean a river or bay, leading to a more recent meaning for Whanganui as big harbour or bay.
The name Manawatū originates from the story of ancestor Haunui-a-Nanaia, who went searching for his wife and named the waterways as he moved south. A waiata (song) describes how his manawa (heart) stopped still, "tū", when he saw the river. Manawatū combines the two words.