Waiwhetū is an eastern suburb of Lower Hutt in the Wellington Region situated in the south of the North Island of New Zealand.

In the 19th-century period of European settlement land at Waiwhetū was worked by Irish-born Alfred Ludlam, who was a member of three of New Zealand's four earliest parliaments. In the 1840s land was set aside by the New Zealand Company as a native reserve for the Te Āti Awa tribe.

From the 1890s to 1939, a flock mill operated on the bank of the Waiwhetū Stream. In the 1930s the New Zealand government compulsorily acquired land at Waiwhetū and built new homes for Te Āti Awa.

Waiwhetū statistical area covers 1.68 km (0.65 sq mi). It had an estimated population of 4,940 as of June 2024, with a population density of 2,940 people per km.

Historical population

Year	Pop.	±% p.a.
2006	3,951	—
2013	3,963	+0.04%
2018	4,305	+1.67%
Source:

Waiwhetū had a population of 4,305 at the 2018 New Zealand census, an increase of 342 people (8.6%) since the 2013 census, and an increase of 354 people (9.0%) since the 2006 census. There were 1,590 households, comprising 2,097 males and 2,208 females, giving a sex ratio of 0.95 males per female. The median age was 35.5 years (compared with 37.4 years nationally), with 852 people (19.8%) aged under 15 years, 906 (21.0%) aged 15 to 29, 2,025 (47.0%) aged 30 to 64, and 519 (12.1%) aged 65 or older.

Ethnicities were 58.7% European/Pākehā, 20.4% Māori, 9.7% Pasifika, 21.7% Asian, and 4.2% other ethnicities. People may identify with more than one ethnicity.

The percentage of people born overseas was 29.8, compared with 27.1% nationally.

Although some people chose not to answer the census's question about religious affiliation, 44.0% had no religion, 37.0% were Christian, 1.1% had Māori religious beliefs, 6.6% were Hindu, 2.3% were Muslim, 1.3% were Buddhist and 2.3% had other religions.

Of those at least 15 years old, 945 (27.4%) people had a bachelor's or higher degree, and 546 (15.8%) people had no formal qualifications. The median income was $33,600, compared with $31,800 nationally. 657 people (19.0%) earned over $70,000 compared to 17.2% nationally. The employment status of those at least 15 was that 1,779 (51.5%) people were employed full-time, 504 (14.6%) were part-time, and 198 (5.7%) were unemployed.

The suburb includes Waiwhetū Marae, a marae (tribal meeting ground) of Taranaki Whānui ki te Upoko o te Ika and of Te Āti Awa. The marae, founded in 1960, includes the Arohanui ki te Tangata wharenui (meeting house). The marae is associated with Īhāia Puketapu, whose vision drove the project to build it.

Waiwhetū Marae features a number of significant carvings and has associations with a number of notable Māori artists. Some of the carvings had been created for the New Zealand Centennial Exhibition in 1940, and others were made specifically for the marae. The head carver was Hōne Te Kauru Taiapa, and other artists include Rangi Hetet, his wife Erenora Puketapu-Hetet (daughter of Īhaīa Puketapu) and their daughter Veranoa Hetet.

Our Lady of Rosary School is a co-educational state-integrated Catholic primary school for Year 1 to 8 students, with a roll of 287 as of August 2024.

The Waiwhetū Stream is a small watercourse that flows through the suburb and drains the eastern side of the Hutt Valley. It enters Wellington Harbour at the Hutt River estuary. Development and urbanisation of the Hutt Valley since the arrival of settlers led to increasing pollution and degradation of the stream environment. The stream was diverted into concrete culverts in many sections in an attempt to reduce flooding. Industrial development in the area around the lower reaches of the stream led to that section becoming an industrial sewer. In 2010, the stream was described as one of the most polluted waterways in New Zealand.

Pressure from the community beginning around 2003 helped to trigger a major project to clean up the lower reaches. This project was declared complete in June 2010, after the removal of 56,000 tonnes of toxic waste. In 2010-11, a community group was formed to lead restoration of the upper reaches of the stream. Over a period of 10 years, volunteers cleared invasive aquatic weeds and rubbish from 6 kilometres (3.7 mi) of the stream bed and established around 34,000 locally-sourced native plants on the banks of the stream.