As of 2020, the population density for the United Kingdom was 276 people per square kilometer, with London having by far the highest number of people per square km, at more than 5.7 thousand. Of the countries which make up the United Kingdom, England the most densely populated at 434 people per square kilometer. Scotland, by contrast, is the most sparsely populated country in the United Kingdom, with only 70 people per square kilometer.
UK population over 66 million
According to the official mid-year population estimate, the population of the United Kingdom was almost 67 million in 2020. Most of the population lived in England, where an estimated 56.28 million people resided, followed by Scotland at 5.4 million, Wales with 3.1 million and finally Northern Ireland at just under 1.9 million.
London calling
Within England, the South East was the region with the highest population at over 9 million, followed by the London region at around 8.8 million. In terms of urban areas, Greater London is the largest city in the United Kingdom, followed by the West Midlands centered around Birmingham and then Greater Manchester in the North West of England.