Riwaka (Māori: Riuwaka) is a small settlement in the Tasman District of New Zealand's South Island. It lies beside Tasman Bay / Te Tai-o-Aorere, five kilometres north of Motueka, and close to the mouth of the Riuwaka River. The land where the town is based was a swamp known as Tureauraki. Europeans first settled in Riwaka in May 1842. The Riwaka economy has been based around growing tobacco and hops.

The settlement's name, Riwaka, is a corruption of the Māori name Riuwaka, which derives from riu meaning bilge or interior, and waka meaning canoe. The name can be interpreted as the hull of the canoe.

The name of the nearby river was officially altered from Riwaka River to Riuwaka River in August 2014, following the Treaty of Waitangi settlements between the Crown and local iwi Ngāti Rārua and Te Atiawa o Te Waka-a-Māui.

Riwaka is described by Statistics New Zealand as a rural settlement. It covers 5.49 km (2.12 sq mi) and had an estimated population of 810 as of June 2024, with a population density of 148 people per km. It is part of the larger Kaiteriteri-Riwaka statistical area]].

Historical population for Riwaka

Year	Pop.	±% p.a.
2006	630	—
2013	657	+0.60%
2018	765	+3.09%
Source:

Riwaka had a population of 765 at the 2018 New Zealand census, an increase of 108 people (16.4%) since the 2013 census, and an increase of 135 people (21.4%) since the 2006 census. There were 270 households, comprising 396 males and 372 females, giving a sex ratio of 1.06 males per female, with 168 people (22.0%) aged under 15 years, 117 (15.3%) aged 15 to 29, 366 (47.8%) aged 30 to 64, and 111 (14.5%) aged 65 or older.

Ethnicities were 92.5% European/Pākehā, 14.1% Māori, 1.6% Pasifika, 2.0% Asian, and 2.7% other ethnicities. People may identify with more than one ethnicity.

Although some people chose not to answer the census's question about religious affiliation, 66.3% had no religion, 21.2% were Christian, 0.4% had Māori religious beliefs, 0.4% were Hindu, 0.4% were Buddhist and 3.1% had other religions.

Of those at least 15 years old, 96 (16.1%) people had a bachelor's or higher degree, and 114 (19.1%) people had no formal qualifications. 69 people (11.6%) earned over $70,000 compared to 17.2% nationally. The employment status of those at least 15 was that 333 (55.8%) people were employed full-time, 96 (16.1%) were part-time, and 12 (2.0%) were unemployed.

Kaiteriteri-Riwaka statistical area, which also includes Mārahau and Kaiteriteri, covers 29.48 km (11.38 sq mi) and had an estimated population of 1,990 as of June 2024, with a population density of 68 people per km.

Historical population for Kaiteriteri-Riwaka

Year	Pop.	±% p.a.
2006	1,464	—
2013	1,539	+0.72%
2018	1,761	+2.73%
Source:

Before the 2023 census, Kaiteriteri-Riwaka had a smaller boundary, covering 28.57 km (11.03 sq mi). Using that boundary, Kaiteriteri-Riwaka had a population of 1,761 at the 2018 New Zealand census, an increase of 222 people (14.4%) since the 2013 census, and an increase of 297 people (20.3%) since the 2006 census. There were 591 households, comprising 915 males and 846 females, giving a sex ratio of 1.08 males per female. The median age was 44.5 years (compared with 37.4 years nationally), with 297 people (16.9%) aged under 15 years, 273 (15.5%) aged 15 to 29, 888 (50.4%) aged 30 to 64, and 306 (17.4%) aged 65 or older.

Ethnicities were 90.5% European/Pākehā, 10.4% Māori, 4.9% Pasifika, 1.4% Asian, and 2.7% other ethnicities. People may identify with more than one ethnicity.

The percentage of people born overseas was 23.7, compared with 27.1% nationally.

Although some people chose not to answer the census's question about religious affiliation, 62.5% had no religion, 26.1% were Christian, 0.7% had Māori religious beliefs, 0.2% were Hindu, 0.5% were Buddhist and 2.7% had other religions.

Of those at least 15 years old, 240 (16.4%) people had a bachelor's or higher degree, and 258 (17.6%) people had no formal qualifications. The median income was $29,000, compared with $31,800 nationally. 162 people (11.1%) earned over $70,000 compared to 17.2% nationally. The employment status of those at least 15 was that 747 (51.0%) people were employed full-time, 279 (19.1%) were part-time, and 36 (2.5%) were unemployed.

The Saint Barnabas Anglican church is located on Main Road, Riwaka.

Riwaka School is a co-educational state primary school for Year 1 to 8 students, with a roll of 178 as of August 2024. The school, opened in 1848, is one of the oldest schools in New Zealand.