Castlereagh population

56,679people · latest estimate

By James Burfield, SEO consultant, Bath · Page updated 18 September 2026 · GeoNames · World Gazetteer 2005

Castlereagh has a population of 56,679, making it the 2nd largest place in City of Belfast. In 2005 the World Gazetteer recorded 56,679, a rise of 0.0% since.

56,679

in 2005

+0.0%

since 2005

of 2 in City of Belfast

The 2005 figure is from the World Gazetteer archive and may draw its boundary differently from the current source, so treat the change as indicative. Sources: method.

Castlereagh in context

4 km

north-west to Belfast, the nearest larger town

515,458

people live within 10 km

#218

largest of 6,358 UK places

Distances are straight-line from the settlement's recorded coordinates. The 10 km figure sums the recorded places within that radius, so it describes how built-up the surroundings are rather than people per square kilometre.

The population, measured on a real boundary

What you mean	Population	Source
Metropolitan Castlereagh settlement NISRA's settlement boundary: the built-up Castlereagh	59,198	Census 2021
Castlereagh (GeoNames record) the figure in this page's heading; boundary unstated	56,679	GeoNames

The census figure is NISRA's Census 2021 count of usual residents inside the settlement's development limit: a boundary drawn in 2014–15 holding 2021 people, so growth at the edges since then sits outside it. 25,467 households. Where the rows disagree, quote the census. Northern Ireland's other layers wait on data that is either licensed (postcodes) or published only at district level (crime), and those absences are deliberate.

Common questions

What is the population of Castlereagh?

The populated place itself holds 56,679 residents. Each figure describes a different boundary and all are correct; the meanings table on this page says which is which, because a population without its boundary is not an answer.

Nearby in City of Belfast

#	Place	Population
1	Belfast	348,005

All 2 places in City of Belfast →