Glenavy is a small town in the South Island of New Zealand. It is located at the southern extreme of the Canterbury region on the alluvial fan of the Waitaki River, three kilometres from the river's outflow into the Pacific Ocean.

Glenavy was named for Glenavy, Northern Ireland, the birthplace of former New Zealand Premier John Ballance.

Glenavy is described as a rural settlement by Statistics New Zealand, and covers 2.40 km (0.93 sq mi). It had an estimated population of 230 as of June 2024, with a population density of 96 people per km. The settlement is part of the larger Morven-Glenavy-Ikawai statistical area.

Historical population for Glenavy

Year	Pop.	±% p.a.
2006	129	—
2013	201	+6.54%
2018	195	−0.60%
Source:

Glenavy had a population of 195 at the 2018 New Zealand census, a decrease of 6 people (−3.0%) since the 2013 census, and an increase of 66 people (51.2%) since the 2006 census. There were 105 households, comprising 105 males and 90 females, giving a sex ratio of 1.17 males per female. The median age was 58.4 years (compared with 37.4 years nationally), with 18 people (9.2%) aged under 15 years, 30 (15.4%) aged 15 to 29, 78 (40.0%) aged 30 to 64, and 69 (35.4%) aged 65 or older.

Ethnicities were 87.7% European/Pākehā, 12.3% Māori, 9.2% Asian, and 1.5% other ethnicities. People may identify with more than one ethnicity.

Although some people chose not to answer the census's question about religious affiliation, 43.1% had no religion, and 40.0% were Christian.

Of those at least 15 years old, 15 (8.5%) people had a bachelor's or higher degree, and 60 (33.9%) people had no formal qualifications. The median income was $23,000, compared with $31,800 nationally. 3 people (1.7%) earned over $70,000 compared to 17.2% nationally. The employment status of those at least 15 was that 57 (32.2%) people were employed full-time, 21 (11.9%) were part-time, and 6 (3.4%) were unemployed.

The Morven-Glenavy-Ikawai statistical area covers 386.32 km (149.16 sq mi) and had an estimated population of 1,310 as of June 2024, with a population density of 3.4 people per km.

Historical population for Morven-Glenavy-Ikawai

Year	Pop.	±% p.a.
2006	939	—
2013	1,131	+2.69%
2018	1,095	−0.64%
Source:

Morven-Glenavy-Ikawai had a population of 1,095 at the 2018 New Zealand census, a decrease of 36 people (−3.2%) since the 2013 census, and an increase of 156 people (16.6%) since the 2006 census. There were 441 households, comprising 597 males and 501 females, giving a sex ratio of 1.19 males per female. The median age was 36.3 years (compared with 37.4 years nationally), with 219 people (20.0%) aged under 15 years, 219 (20.0%) aged 15 to 29, 534 (48.8%) aged 30 to 64, and 126 (11.5%) aged 65 or older.

Ethnicities were 75.9% European/Pākehā, 8.8% Māori, 0.8% Pasifika, 19.2% Asian, and 2.5% other ethnicities. People may identify with more than one ethnicity.

The percentage of people born overseas was 24.7, compared with 27.1% nationally.

Although some people chose not to answer the census's question about religious affiliation, 46.8% had no religion, 36.2% were Christian, 0.5% had Māori religious beliefs, 5.2% were Hindu, 0.3% were Muslim, 1.9% were Buddhist and 1.9% had other religions.

Of those at least 15 years old, 141 (16.1%) people had a bachelor's or higher degree, and 183 (20.9%) people had no formal qualifications. The median income was $40,600, compared with $31,800 nationally. 111 people (12.7%) earned over $70,000 compared to 17.2% nationally. The employment status of those at least 15 was that 528 (60.3%) people were employed full-time, 117 (13.4%) were part-time, and 24 (2.7%) were unemployed.

Glenavy School is a full primary school serving years 1 to 8, with a roll of 127 students as of August 2024. The school opened in 1889.