Local government in Whanganui began with the creation of the Wanganui Town Board, within Wellington Province, in 1862.

[7][8] In October 2023 the council voted to establish a Māori ward for the 2025 and 2028 local elections.

[9][10] The elected mayor and councillors provide governance for the city by setting the policy direction of the council, monitoring its performance, representing the city's interests, and employing the Chief Executive.

The Whanganui Rural Community Board consists of seven elected members.

The flag consists of the coat of arms with the Māori and English names of the council beneath it in white, all on a blue field.