The suburb of Plimmerton lies in the northwest part of the city of Porirua in New Zealand, adjacent to some of the city's more congenial beaches. State Highway 59 and the North Island Main Trunk railway line pass just east of the main shopping and residential area.

Porirua, a city in the Wellington Region of the North Island of New Zealand, is one of the four cities that constitute the Wellington metropolitan area. The name 'Porirua' is a corruption of 'Pari-rua', meaning "the tide sweeping up both reaches". It almost completely surrounds Porirua Harbour at the southern end of the Kāpiti Coast. As of June 2023, Porirua has a population of 60,900.