Belfast (from Irish: Béal Feirste, meaning "mouth of the Shoal") is the capital of and largest city in Northern Ireland. By population, it is the 14th biggest city in the United Kingdom and 2nd largest on the island of Ireland. It is the seat of the devolved government and legislative Northern Ireland Assembly. The city of Belfast has a population of 267,500 and lies at the heart of the Belfast urban area, which has a population of 483,418. The Larger Urban Zone, as defined by the European Union, has a total population 641,638. Belfast was granted city status in 1888.

Historically, Belfast has been a centre for the Irish linen industry (earning the nickname "Linenopolis"), tobacco production, rope-making and shipbuilding: the city's main shipbuilders, Harland and Wolff, which built the well-known RMS Titanic, propelled Belfast on to the global stage in the early 20th century as the biggest and most productive shipyard in the world. Belfast played a key role in the Industrial Revolution, establishing its place as a global industrial centre until the latter half of the 20th century. Industrialisation and the inward migration it brought made Belfast, if briefly, the biggest city in Ireland at the turn of the 20th century and the city's industrial and economic success was cited by Ulster unionist opponents of Home Rule as a reason why Ireland should shun devolution and later why Ulster in particular would fight to resist it.