Dome Valley had a population of 249 at the 2018 New Zealand census, a decrease of 12 people (−4.6%) since the 2013 census, and an increase of 24 people (10.7%) since the 2006 census. There were 75 households, comprising 126 males and 126 females, giving a sex ratio of 1.0 males per female, with 48 people (19.3%) aged under 15 years, 30 (12.0%) aged 15 to 29, 120 (48.2%) aged 30 to 64, and 45 (18.1%) aged 65 or older.
