Taumarunui Ward representative Karen Ngatai is now the Ruapehu District's deputy mayor.
Ngatai takes over following the sudden death of former deputy mayor Marion Gillard, and she will also sit on council's district māori council and audit and risk committee.
Ngatai has been a councillor since 2004 and has been heavily involved in the Taumarunui Revitalisation Taskforce.
She had been dedicated to her community, Mayor Don Cameron said, and spent many hours planting and caring for rhododendrons between Taumarunui and Manunui.
Ngatai said the appointment was tinged with sadness for her, because Gillard was her friend. She knew she had big shoes to fill, and was proud to fill them.
Gillard represented the Ohura Ward in the Ruapehu District and councillors have decided to hold a by-election to replace her.
Nominations can be made between September 6 and October 4. If there is more than one nomination an election will be held, with papers sent out on November 8.
Election day will be November 30, and a final declaration will be made on December 6.