Sefton is a small town in the Waimakariri District, New Zealand, about 23 miles from Christchurch.^[3]

In 1886, it had a census population of 276 and was a station on the Christchurch Ashley line.^[3] In 1891 it had a population of 390, of which 202 were male and 188 were female.^[4] In the 2018 census, the population was 207.^[5]

Sefton has one school: Sefton School (est. 1884).^[6] It is a decile 7 state non-integrated co-educational full primary, with 128 students (as of February 2024).^[7] The principal is Heidi Moeller-Kemp.

Sefton is described by Statistics New Zealand as a rural settlement and covers 0.87 km² (0.34 sq mi).^[1] It had an estimated population of 240 as of June 2023,^[2] with a population density of 276 people per km². Sefton is part of the larger Ashley-Sefton statistical area.^[8]

Sefton had a population of 207 at the 2018 New Zealand census, a decrease of 18 people (−8.0%) since the 2013 census, and a decrease of 24 people (−10.4%) since the 2006 census. There were 84 households, comprising 117 males and 93 females, giving a sex ratio of 1.26 males per female. The median age was 41.2 years (compared with 37.4 years nationally), with 45 people (21.7%) aged under 15 years, 27 (13.0%) aged 15 to 29, 102 (49.3%) aged 30 to 64, and 33 (15.9%) aged 65 or older.

Ethnicities were 95.7% European/Pākehā, 5.8% Māori, 2.9% 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, 65.2% had no religion, 26.1% were Christian, and 2.9% were Muslim.

Of those at least 15 years old, 21 (13.0%) people had a bachelor's or higher degree, and 51 (31.5%) people had no formal qualifications. The median income was $32,600, compared with $31,800 nationally. 21 people (13.0%) earned over $70,000 compared to 17.2% nationally. The employment status of those at least 15 was that 78 (48.1%) people were employed full-time, 36 (22.2%) were part-time, and 3 (1.9%) were unemployed.^[5]