Porirua is a city in the Wellington Region of New Zealand, immediately north of the city of Wellington, with their central business districts 20 km apart.
A large proportion of the population commutes to Wellington, so it may be considered a satellite city. It almost completely surrounds Porirua Harbour at the southern end of the Kapiti Coast. The eastern (Pauatahanui) inlet of the harbour is notable for its world-class estuarine values.
The population at the June 2011 estimate was 52,500.