Based on the most recent 2021 Census data (analyzed through 2026), the "whitest" major city in the UK is often cited as Swansea (Wales) or Plymouth (England), both of which report a white population exceeding 92–94%. However, when looking at larger urban centers, Belfast in Northern Ireland has historically recorded the highest percentage of white residents, often hovering around 96%. It is important to distinguish between "major cities" and "districts"; many smaller cathedral cities in the North East or South West of England have even higher percentages, but they are not classified as major metropolitan hubs. In 2026, demographic trends in the UK show increasing diversity even in historically homogenous areas, but coastal cities in the South West and large parts of Scotland and Northern Ireland remain significantly less diverse than London, Birmingham, or Manchester, where the white British population is often below 40–50% in the central districts.