A state church does not exist in Germany. The national constitutions of 1919 and 1949 guarantee freedom of faith and religion. The modern constitution of 1949 also states that no one may be discriminated against due to their faith or religious opinions.

Christianity is the largest religion in Germany, with around 51.5 million adherents (62.8%) in 2008. Relative to the whole population, 30.0% of Germans are Catholics, 29.9% are Protestants belonging to the Evangelical Church in Germany (EKD), and the remaining Christians belong to smaller denominations each with less than 0.5% of the German population. Protestantism is concentrated in the north and east and Roman Catholicism is concentrated in the south and west; 1.6% of the country's overall population declare themselves Orthodox Christians.

The second largest religion is Islam with an estimated 3.8 to 4.3 million adherents (4.6% to 5.2%), followed by Buddhism with 250,000 and Judaism with around 200,000 adherents (0.3%); Hinduism has some 90,000 adherents (0.1%). All other religious communities in Germany have fewer than 50,000 adherents. Of the roughly 4 million Muslims, most are Sunnis and Alevites from Turkey, but there are a small number of Shi'ites and other denominations.[162] German Muslims, a large portion of whom are of Turkish origin, lack full official state recognition of their religious community. Germany has Europe's third largest Jewish population (after France and the United Kingdom). Approximately 50% of the Buddhists in Germany are Asian immigrants.

Germans with no stated religious adherence make up 34.1% of the population and are concentrated in the former East Germany and major metropolitan areas. German reunification in 1990 greatly increased the country's non-religious population, a legacy of the state atheism of the previously Soviet-controlled East. Christian church membership has decreased in recent decades, particularly among Protestants.