Spain

Spain leads Western Europe in population growth, reaching 49.3 million across 505,992 square kilometers, with a year-over-year increase of 0.4%—outpacing #5 Italy's decline by 0.7 percentage points. Immigration accounts for 85% of this growth, adding over 400,000 newcomers annually, more than the typical rival in the region. However, the fertility rate of 1.3 children per woman is 0.2 higher than Italy's but still 0.2 below the EU average, while separatist tensions in Catalonia simmer despite the demographic boost.