Outgoing Civil Defence Minister John Carter will be the next High Commissioner to the Cook Islands.
Mr Carter has been a National MP since 1987 - currently for Northland and previously for the Bay of Islands.
He announced in November that he would not be standing at this year's general election.
Foreign Affairs Minister Murray McCully says Mr Carter has a long association with the Cook Islands and will take a leadership role as New Zealand aid to the Pacific nation is refocused on sustainable economic development.
Mr Carter will take up his appointment in August, replacing Linda Te Puni.