The population of the United Kingdom was estimated at 69.3 million in 2024. It is the 21st most populated country in the world and has a population density of 285 peopleĀ per square kilometre (740 people/sqĀ mi), with England having significantly greater density than Wales, Scotland, and Northern Ireland. Almost a third of the population lives in south east England, which is predominantly urban and suburban, with 9,089,736 people in the capital city, London, whose population density was 5,782 inhabitants per square kilometre (14,980/sqĀ mi) in 2024.
The population of the UK has undergone demographic transitionā from a typically pre-industrial population, with high birth and mortality rates and slow population growth, through a stage of falling mortality and faster rates of population growth, to a stage of low birth and mortality rates with, again, lower rates of growth. This growth through 'natural change' has been accompanied in the past three decades by growth through net immigration into the United Kingdom, which since 1999 has exceeded natural change.