The Prime Minister's father Ross Ardern will finish up as High Commissioner in Niue and come back to New Zealand, where he will be the new administrator of Tokelau.
Foreign Minister Winston Peters made the announcement today.
The role will be based in Auckland, meaning he will be moving closer to his daughter, having spent many years serving New Zealand in the South Pacific.
He has been High Commissioner since early 2014, and was previously in Samoa as the NZ Police liaison officer for the South Pacific from 2009 to 2013. He was Commissioner of Police for Niue from 2005 to 2009.
He joined the police in 1974 and received a Commissioner's Commendation in 2002 after he peacefully negotiated for three hours with a man armed with a machete.
Peters said Ardern's new role would be to ensure public services were delivered to New Zealand citizens in Tokelau, and helping to manage the relationship between the two countries.
Ardern will also be responsible for overseeing New Zealand's development assistance to Tokelau, which includes major investments in internet connectivity and transport infrastructure.
He will start the new position in the new year.
"Ardern's experience as a High Commissioner, his extensive understanding of the Pacific, and distinguished career with New Zealand Police make him an ideal candidate for this role," Peters said.
"I have no doubt he will make a major contribution to the relationship between New Zealand and Tokelau."
Jacinda Ardern has mentioned her father's role in the Pacific when discussing the challenge of climate change.
"I remember listening to a couple of members of my family discussing climate change a few years ago. It's fair to say they were sceptical," she has said.
"I was waiting for my moment to jump in, when suddenly I heard my father pipe up. 'I don't know much about the science,' he said, 'but I do know what they showed me in Kiribati'."