Spain's Muslim population has grown to 2.5 million people, accounting for around 5% of the country's population, making Islam the country's fastest-growing major religion by demographic growth. The growth is driven primarily by immigration and second-generation Muslims born in Spain. Around 3.6% of Spain's population are first-generation Muslim immigrants, while another 1.4% were born in Spain with at least one Muslim parent. Among younger generations, the trend is even more pronounced: approximately 11% of babies born in Spain in 2024 had at least one Muslim parent, around one in every nine births. The report attributes this largely to Muslim women having fertility rates estimated at two to three times higher than Spanish women. Around 85% of first-generation Muslim immigrants come from Africa, roughly 65% are of Moroccan origin, and the largest Muslim populations are in Catalonia (~700,000), Andalusia (~400,000), and the Valencian Community (~300,000).