Ōhau is a village and semi-rural community in the Horowhenua District and Manawatū-Whanganui region of New Zealand's North Island. It is located just south of Levin on State Highway 1.

The New Zealand Ministry for Culture and Heritage gives a translation of "place of Hau" for Ōhau, but an alternative meaning could be "windy place".

The former Ohau railway station is located in Ohau. It operated from 1886 to 1987, with most services ending in 1971.

The local Kikopiri Marae and Kikopiri meeting house are a tribal meeting ground for the Ngāti Raukawa hapū of Ngāti Hikitanga and Ngāti Kikopiri.

In October 2020, the Government committed $335,056 from the Provincial Growth Fund to upgrade Kikopiri Marae and Kererū Marae, creating 48 jobs.

Ōhau is defined by Statistics New Zealand as a rural settlement and covers 4.47 km (1.73 sq mi). It had an estimated population of 830 as of June 2023, with a population density of 186 people per km. It is part of the larger Ōhau-Manakau statistical area.

Historical population for Ōhau settlement

Year	Pop.	±% p.a.
2006	438	—
2013	561	+3.60%
2018	666	+3.49%
Source:

Before the 2023 census, the settlement had a larger boundary, covering 6.12 km (2.36 sq mi). Using that boundary, Ōhau had a population of 666 at the 2018 New Zealand census, an increase of 105 people (18.7%) since the 2013 census, and an increase of 228 people (52.1%) since the 2006 census. There were 249 households, comprising 351 males and 315 females, giving a sex ratio of 1.11 males per female, with 93 people (14.0%) aged under 15 years, 96 (14.4%) aged 15 to 29, 309 (46.4%) aged 30 to 64, and 168 (25.2%) aged 65 or older.

Ethnicities were 95.5% European/Pākehā, 11.3% Māori, 1.4% Pasifika, 1.8% Asian, and 0.5% other ethnicities. People may identify with more than one ethnicity.

Although some people chose not to answer the census's question about religious affiliation, 52.3% had no religion, 36.0% were Christian, 0.5% had Māori religious beliefs, 0.5% were Hindu, 0.5% were Muslim and 0.9% had other religions.

Of those at least 15 years old, 81 (14.1%) people had a bachelor's or higher degree, and 117 (20.4%) people had no formal qualifications. 93 people (16.2%) earned over $70,000 compared to 17.2% nationally. The employment status of those at least 15 was that 264 (46.1%) people were employed full-time, 87 (15.2%) were part-time, and 15 (2.6%) were unemployed.

Ōhau-Manakau statistical area, which includes Manakau, covers 41.75 km (16.12 sq mi) and had an estimated population of 2,530 as of June 2023, with a population density of 60.60 people per km.

Historical population of Ōhau-Manakau

Year	Pop.	±% p.a.
2006	1,791	—
2013	1,785	−0.05%
2018	2,154	+3.83%
Source:

Before the 2023 census, the statistical area had a larger boundary, covering 42.23 km (16.31 sq mi). Using that boundary, Ōhau-Manakau had a population of 2,154 at the 2018 New Zealand census, an increase of 369 people (20.7%) since the 2013 census, and an increase of 363 people (20.3%) since the 2006 census. There were 825 households, comprising 1,086 males and 1,065 females, giving a sex ratio of 1.02 males per female. The median age was 51.4 years (compared with 37.4 years nationally), with 318 people (14.8%) aged under 15 years, 291 (13.5%) aged 15 to 29, 969 (45.0%) aged 30 to 64, and 573 (26.6%) aged 65 or older.

Ethnicities were 84.7% European/Pākehā, 17.3% Māori, 3.1% Pasifika, 5.2% Asian, and 1.0% other ethnicities. People may identify with more than one ethnicity.

The percentage of people born overseas was 17.1, compared with 27.1% nationally.

Although some people chose not to answer the census's question about religious affiliation, 52.8% had no religion, 35.1% were Christian, 0.4% had Māori religious beliefs, 0.6% were Hindu, 0.1% were Muslim, 0.4% were Buddhist and 1.5% had other religions.

Of those at least 15 years old, 249 (13.6%) people had a bachelor's or higher degree, and 441 (24.0%) people had no formal qualifications. The median income was $27,600, compared with $31,800 nationally. 243 people (13.2%) earned over $70,000 compared to 17.2% nationally. The employment status of those at least 15 was that 849 (46.2%) people were employed full-time, 255 (13.9%) were part-time, and 60 (3.3%) were unemployed.

Ōhau School is a co-educational state primary school for Year 1 to 8 students, with a roll of 152 as of August 2024.