Inangahua is a small settlement in the northwest of New Zealand's South Island. It consists of three settled areas: Inangahua Junction at the confluence of the Inangahua and Buller Rivers, 34 kilometres (21 mi) north of Reefton and 46 kilometres (29 mi) southeast of Westport; Inagahua Landing, 10 km further up the Inangahua River; and Inangauhua township, 2 km east of the Junction. Murchison is 52 kilometres (32 mi) further east.^[4][5] After the 1968 Inangahua Earthquake, most of the inhabitants left the area or shifted to the township, which is now the population centre and known simply as Inangahua.

Inangahua's main industries include forestry, coal, farming and sawmilling. There is a small primary school, shops, fire station and earthquake museum.

The name of the town refers to inanga, the Māori word for whitebait (Galaxias spp.) and hua, the act of drying and preserving them in sealed containers; the river was known for its abundance of fish.^[6] Inangahua Junction was formerly known as Christies Junction.

Before the construction of the Buller Gorge road, the only way to travel inland from Westport was by river. At the beginning of the West Coast gold rush, mining equipment and quartz-crushing machinery was ferried up the Buller River to its confluence with the Inangahua, then about 10 km up the Inanghua as far as "The Landing", from which it was transported overland south to Reefton. At the height of the gold rush over 1000 prospectors were working in tributaries of the Inangahua.

The town was substantially affected by an earthquake on Friday, 24 May 1968. At 5:24 am, the earthquake measuring 7.1 on the Richter scale struck the town, and many landslides and aftershocks followed. The entire population of around 100 was temporarily evacuated. There were no fatalities in the town, but a woman and her visiting mother were killed when the house they were in, along the Inangahua Junction to Westport road, was crushed by a landslide on the cliffs above their house,^[7] while a man died near Greymouth when his car hit a section of road on that suddenly subsided on the run-up to a bridge.^[8] Another three died days later when a helicopter surveying downed telephone lines crashed.^[9]

Inangahua Junction is in an SA1 statistical area which covers 412.43 km² (159.24 sq mi).^[2] The SA1 area is part of the larger Inangahua statistical area.

The SA1 area had a population of 102 at the 2018 New Zealand census, a decrease of 42 people (−29.2%) since the 2013 census, and a decrease of 57 people (−35.8%) since the 2006 census. There were 51 households, comprising 60 males and 45 females, giving a sex ratio of 1.33 males per female. The median age was 40.5 years (compared with 37.4 years nationally), with 24 people (23.5%) aged under 15 years, 15 (14.7%) aged 15 to 29, 54 (52.9%) aged 30 to 64, and 12 (11.8%) aged 65 or older.

Ethnicities were 85.3% European/Pākehā, 5.9% Māori, 8.8% Asian, and 2.9% other ethnicities. People may identify with more than one ethnicity.

Although some people chose not to answer the census's question about religious affiliation, 58.8% had no religion, 23.5% were Christian, 8.8% were Hindu and 2.9% had other religions.

Of those at least 15 years old, 21 (26.9%) people had no formal qualifications. The median income was $20,900, compared with $31,800 nationally. 6 people (7.7%) earned over $70,000 compared to 17.2% nationally. The employment status of those at least 15 was that 39 (50.0%) people were employed full-time, 12 (15.4%) were part-time, and 3 (3.8%) were unemployed.^[3]

Inangahua Junction is located on the Stillwater - Westport Line railway, and was intended to be the junction of this line with the never-completed Nelson Section. In 1914, the railway was opened to Inangahua Junction from its former terminus in Cronadun, but subsequent progress through the Buller Gorge was slow. In July 1942, trains began running the full length of the line between Stillwater and Westport, but the line was not officially opened until 5 December 1943. With the commencement of through services, passenger trains were operated by RM class Vulcan railcars, which connected in Stillwater with services that ran along the Midland Line between Greymouth and Christchurch. In 1967, the passenger services ceased, and today, the primary traffic is coal, with multiple coal trains passing through Inangahua Junction daily. Today the town is served by the daily inter city bus between Nelson and Westport.

Inangaha was the host of the PHAT New Year's Eve music festivals. PHAT07, PHAT08, PHAT09, PHAT10 (with Australian band Pendulum and NZers Black Seeds, Kora, Salmonella Dub, Tiki and Concord Dawn),^[12] PHAT11 featured New Zealand and many international acts. PHAT is held on flat clearings surrounded by native bush on Rough Creek Road, off Browns Creek Road, south of Inangahua and owned by the Storer family. Approximately 5000 people attend the PHAT music festivals, with 48+ hours of continuous performance on two stages.

The other annual event held on the Inangahua site was PHAT MOON, a slightly smaller version of the bigger New Year's Eve's event.

PHAT MOON was held over Easter weekend. The music runs for 24 hours, but people are invited to come and camp the night before. This ceased quite a few years ago; the site has returned to being a farm.

Inangahua Junction School was a coeducational contributing primary (years 1–6) school. The school was in existence in 1887.^[13] It closed in 2018.^[14]

Inangahua College merged with Reefton School to form Reefton Area School in 2004.^[15] The College, which existed for 38 years, replaced the Reefton District High School.^[16]