Denmark's population remains formally majority Lutheran, with around 70 to 75 percent belonging to the state Church of Denmark (Folkekirken) by registration, though active practice and belief are markedly lower, and religiously unaffiliated and non-practicing residents make up a large and growing share alongside Muslim and small Catholic minorities, per estimates including Pew Research's Religious Composition of the World, 2010-2020.
Denmark adopted Lutheranism as state religion in 1536 under King Christian III during the Reformation, seizing Catholic Church properties and establishing the monarch as the church's formal head, a role the Danish constitution still assigns to the sovereign today. Viking-era Norse paganism, centered on gods including Odin and Thor, persisted alongside gradual Christianization from the ninth and tenth centuries, commemorated at sites such as the Jelling stones, raised by King Harald Bluetooth around 965 CE to mark Denmark's Christianization.
Denmark's Muslim population, chiefly of Turkish, Pakistani, Middle Eastern and Somali background, grew substantially through late-twentieth-century labor migration and subsequent refugee resettlement, becoming the country's largest religious minority and a recurring subject of Danish immigration and integration debate.