Sir Henry van der Heyden will take a board seat with Tainui Group Holdings, the commercial arm of the Waikato-Tainui iwi.
Sir Henry, who will step down as chairman of Fonterra later this year, will replace John Spencer, who resigns from Tainui Group's board at the end of June, after ten years as chairman.
Tainui Group chief executive Mike Pohio says Sir Henry will bring very strong governance skills to the board table.
"He has a very strong familiarity with the area in which Tainui Group Holdings predominantly operates. He's a Waikato man and we're very pleased to have that very strong level of governance," he says.
Mr Pohio says Sir Henry will be one of three independent directors on Tainui Group's board.
Meanwhile, professional director and accountant Joanna Perry, will join the board as a specialist adviser.
Ms Perry is on the boards of Genesis Energy, Trade Me, The Co-operative Bank, Rowing New Zealand and Sport and Recreation New Zealand.
Tainui Group's board will elect a new chairman at its first meeting after the changeover.