As of January 1, 2023, the European Union (EU) has a population of 448.8 million people. Germany is the most populous EU country, with 84.4 million residents (19% of the EU total), followed by France (68.2 million, 15%), Italy (59.0 million, 13%), Spain (48.1 million, 11%), and Poland (36.8 million, 8%). Together, these five countries account for 66% of the EU's population, according to Eurostat. On the opposite end, the least populated EU countries are Malta (542,000, 0.1% of the EU total), Luxembourg (661,000, 0.1%), and Cyprus (921,000, 0.2%).

From January 1, 2003, to January 1, 2023, the EU's total population grew from 431.2 million to 448.8 million, marking a 4% increase. During this period, 18 EU countries experienced population growth, while nine saw a decline. Luxembourg (47%), Malta (36%), Ireland (33%), and Cyprus (29%) had the largest relative increases. Conversely, Latvia (−18%), Bulgaria and Lithuania (both -17%), and Romania (-12%) saw the most significant relative decreases. France and Spain each recorded the largest absolute population increase (6.3 million), whereas Romania (−2.6 million), Poland (−1.5 million), and Bulgaria (−1.4 million) had the largest absolute decreases.

Population density across the EU varies significantly, from 18 to 1,693 people per km². In 2022, the average population density in the EU was 109 people per km². Malta had the highest population density (1,693 people per km²), followed by the Netherlands (518) and Belgium (384). Finland (18 people per km²) and Sweden (26) had the lowest densities. Comparing 2022 to 2002, 18 EU countries saw an increase in population density, with Malta (from 1,255 to 1,693 people per km²), Luxembourg (from 173 to 253), and Belgium (from 341 to 384) experiencing the largest growth. Romania (from 95 to 81) and Bulgaria (from 71 to 60) saw the biggest decreases. Overall, the EU's average population density increased from 105 people per km² to 109 during this period.