In Northumberland, the population size has increased by 1.4%, from around 316,000 in 2011 to 320,600 in 2021.
Figures from the Office for National Statistics reveal it is also the least densely populated of the North East's 12 local authority areas, with an area equivalent to around two football pitches per resident.
There has been an increase of 28.9% in people aged 65 years and over, a decrease of 5.9% in people aged 15 to 64 years, and a decrease of 3.4% in children aged under 15 years.
Here are the 29 biggest towns in Northumberland ranked by population, according to the 2021 census.
1. Blyth
Blyth is the largest town in Northumberland with a population of 39,732, up from 37,465 in 2011. Photo: Jane Coltman
2. Cramlington
Cramlington is second largest with a population of 28,843, up from 28,395. Photo: Google
3. Ashington
Ashington is third largest with a population of 28,278, up from 27,789 in 2011. Photo: Google
4. Bedlington
Bedlington is the fourth biggest town with a population of 16,193, a slight fall from 16, 348 in 2011. Photo: Google