Ahipene-Mercer is of Māori, Welsh, Swedish, and Scots descent. He descends from the ancient Wellington tribes of Ngai Tara and Ngati Ira. Direct ancestors were members of the Ngati Ira people displaced after conflict in the Wellington area in the 1820s to the Wairarapa. Ahipene Mercer's closest Māori links now are at Pirinoa, and Kohunui Marae, the people of his maternal grandmother. His mother's father, from whom the name "Ahipene" was passed down, was of the Ngati Kahungunu, tribe from the area around Porangahau, and also of Ngāi Tahu descent. This grandfather was also of Scots descent, through James Wybrow, a whaler. There is a strong family link with Ruapuke Island, between Stewart Island and the South Island.