Kai Iwi is a rural community west of Whanganui in New Zealand's North Island. It lies close to SH 3, approximately halfway between Whanganui and Waitotara. The population centre is at Kai Iwi Beach, also called Mowhanau.

The area was settled by Europeans in the 1880s.^[3]

Other than farming, the community's largest industry is its honey factory, which was founded in 2003.^[4]

Kai Iwi is defined by Statistics New Zealand as a rural settlement. It covers 0.88 km² (0.34 sq mi)^[1] and had an estimated population of 170 as of June 2023,^[2] with a population density of 193 people per km². It is part of the larger Mowhanau statistical area.

Kai Iwi had a population of 141 at the 2018 New Zealand census, an increase of 6 people (4.4%) since the 2013 census, and a decrease of 27 people (−16.1%) since the 2006 census. There were 54 households, comprising 78 males and 63 females, giving a sex ratio of 1.24 males per female. The median age was 49.2 years (compared with 37.4 years nationally), with 24 people (17.0%) aged under 15 years, 21 (14.9%) aged 15 to 29, 69 (48.9%) aged 30 to 64, and 27 (19.1%) aged 65 or older.

Ethnicities were 95.7% European/Pākehā, and 14.9% Māori. People may identify with more than one ethnicity.

Although some people chose not to answer the census's question about religious affiliation, 61.7% had no religion, and 36.2% were Christian.

Of those at least 15 years old, 24 (20.5%) people had a bachelor's or higher degree, and 21 (17.9%) people had no formal qualifications. The median income was $31,800, compared with $31,800 nationally. 21 people (17.9%) earned over $70,000 compared to 17.2% nationally. The employment status of those at least 15 was that 57 (48.7%) people were employed full-time, 21 (17.9%) were part-time, and 3 (2.6%) were unemployed.^[5]

Kai Iwi has three marae, affiliated with Ngāti Iti and the Ngā Rauru hapū of Ngāti Pūkeko: Te Aroha Marae and Te Kotahitanga meeting house; Kai Iwi Marae and Awhakaueroa meeting house; and Taipake Marae and Taipake meeting house.^[8][9]

In October 2020, the Government committed $522,926 from the Provincial Growth Fund to upgrade Te Ihupuku Marae, Waipapa Marae and Te Aroha Marae, creating 92 jobs.^[10]

The Kai Iwi area has three artesian bores that are a major source of drinking water for Whanganui.^[11]

Bushy Park Tarapuruhi is a protected native forest reserve and bird sanctuary located 8 kilometres (5.0 mi) inland from Kai Iwi on State Highway 3. The reserve has an area of approximately 100 hectares (250 acres), and includes a homestead that is a Category 1 listed historic place.^[12]

Kai Iwi School is a co-educational state primary school for Year 1 to 8 students,^[13] with a roll of 94 as of February 2024.^[14] The school opened in 1876.^[15]