The number of Catholics in Austria is falling sharply, while its Muslim population continues to grow. By 2024, Catholics in the population numbered 4.56 million with 71,531 leaving the church that year, compared to just over 5,000 joining or returning.
In contrast, by 2021 the total Muslim population was observed to have reached approximately 700,000. Although smaller than the Catholic community, its rapid rate of growth shows a shift in Austria’s religious composition.
The state also collects less data on religion than before, relying now on voluntary surveys rather than mandatory census questions—reflecting a changing relationship between church and society.
This shift is most readily apparent in Vienna’s classrooms, where young Muslims make up the largest religious group.