In 2005, 79% of Lithuanians belonged to the Roman Catholic Church. The Catholic Church has been the majority denomination since the introduction of Christianity to Lithuania in the end of fourteenth century. Some priests actively led the resistance against the Communist regime (symbolized by the Hill of Crosses). After independence was regained, the Catholic Church leads resistance against socialism and liberalism, especially in ethical questions. Church attendance has increased since the end of the Soviet occupation and the country has so far maintained a fairly high level of religious practice.

In the 16th century, Lutheranism started to spread from neighboring Livonia and East Prussia. In the first half of 20th century Lutheran Protestant church had around 200,000 members, 9% of total population, although Lutheranism has declined since 1945. Small Protestant communities are dispersed throughout the northern and western parts of the country. Various Protestant churches have established missions in Lithuania since 1990.

4.9% are Eastern Orthodox (mainly among the Russian minority), 1.9% are Protestant and 9.5% have no religion. The country also has minority communities of Judaism, Islam, and Karaism which make up another 1.6% of the population. According to the most recent Eurobarometer Poll 2005, 49% of Lithuanian citizens responded that "they believe there is a God", 36% answered that "they believe there is some sort of spirit or life force" and 12% that "they do not believe there is any sort of spirit, god, or life force".