It is in the north of the city 10 km (6.2 mi) from Cathedral Square, close to the banks of the Waimakariri River.

It was originally known as North Road District, Seven Mile Peg, Styx, or by its Māori name Purarekanui.

[3] James McNeight Watt (1838–1892) emigrated from Belfast and was a partner with the original meat works, around which the settlement grew.

Before the 2023 census, Belfast had a smaller boundary, covering 5.98 km2 (2.31 sq mi).

Although some people chose not to answer the census's question about religious affiliation, 54.5% had no religion, 33.4% were Christian, 0.3% had Māori religious beliefs, 1.1% were Hindu, 0.4% were Muslim, 0.7% were Buddhist and 2.2% had other religions.