The population of Belfast is 345,418. This is the most recent data from the 2021 census and is a massive 20.8% increase on the population in 2011.
Belfast is an important port and dockyard city, known for its shipbuilding – the Titanic, for example, was built in Belfast. It was granted city status by Queen Victoria in 1888.
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Belfast population growth and decline
The number of people living in Belfast grew rapidly in the 18th and 19th centuries. From a recorded population of just 8,549 people in 1757, the city grew to become a thriving metropolis of 349,180 by 1901.
The partition of Ireland and creation of Northern Ireland did little to slow the city’s growth and, by 1937 just before the start of the Second World War, there were 438,086 living in Belfast.
However, between the 1950s and 1990s the number of people living in the city of Belfast declined rapidly – from 443,671 in 1951 to a low of 277,391 in 2001.
The conflict known as The Troubles, much of which took place in Belfast which were resolved with the Good Friday Agreement in 1998, was a major cause of this population decrease.
But it is important to note that this is not the only reason for population decline in Belfast. Wider demographic trends were also at play, and other major cities in the UK and Ireland that had thrived in the 19th century and early 20th century – such as London, Dublin, Birmingham and Manchester – also saw similar declines.
Since the 1990s, the population has steadily and rapidly increased again and Belfast is an increasingly safe and vibrant city.
Belfast Religious Demographics
The Catholic population of Belfast has been steadily increasing, in contrast to the Protestant population which, as elsewhere in Northern Ireland, continues to fall.
The 2021 census confirmed that 43% of people in Belfast were Catholic. Other religions are as follows: 12% Presbyterian, 8% for the Church of Ireland, 3% Methodist, 6% of Christian religions, 3% other religions and 24% no religion or not stated
- Religion not stated / No religion – 24%
- Presbyterian – 12%
- Church of Ireland – 8%
- Methodist – 3%
- Other Christian religions – 6%
- Other religions – 3%
Belfast Ethnic Demographics
In common with the rest of Northern Ireland, Belfast’s population is overwhelmingly white.
The 2021 census reported that 93% of people in Belfast were white, although this is a significant change from 2011 when the city was 98% white.
For comparison, 96.8% of people across the whole of Northern Ireland (including Belfast) reported that they were white
Belfast National Identity
Because the island of Ireland is divided across two countries, national identity is also an important demographic category in Northern Ireland.
In Belfast in 2021, the single largest national identity grouping was ‘Irish only’, representing 35% of people in the city.
Other national identities reported were:
- British only – 27%
- Northern Irish only – 17%
- British and Northern Irish only – 7%
- Irish and Northern Irish only – 2%
- British, Irish and Northern Irish only – 2%
- British and Irish – under 1%
- Other identities – 10%
Belfast population by year
The table below lists the population of Belfast at the time of each census:
What county is Belfast in?
Most of Belfast city (the part to the left of the river Lagan) is in County Antrim. The rest of the city is also in County Down.
You can read more about the counties of Ireland in our separate article.