The U.S. government estimates the total population at 7.0 million (midyear 2020 estimate). According to the 2011 census (the most recent), 76 percent of the population identifies as Eastern Orthodox Christian, primarily affiliated with the BOC. The census reports Muslims, the second largest religious group, are approximately 10 percent of the population, followed by Protestants at 1.1 percent and Roman Catholics at 0.8 percent. Nearly 95 percent of Muslims reported being Sunni; most of the rest are Shia, and there is a small number of Ahmadis concentrated in Blagoevgrad. Orthodox Christians of the Armenian Apostolic Orthodox Church, Jews, Jehovah’s Witnesses, members of the Church of Jesus Christ, Sri Chinmoy, and other groups together make up 0.2 percent of the population. According to the census, 4.8 percent of respondents have no religion and 7.1 percent did not specify a religion. According to a 2019 report by the think tank Agency for Social Analyses, 74 percent of individuals identify as Orthodox Christians, 10 percent as Muslims, 13 percent as atheists, and 3 percent with other religious traditions.

Some religious minorities are concentrated geographically. Many Muslims, including ethnic Turks, Roma, and Pomaks (descendants of Slavic Bulgarians who converted to Islam under Ottoman rule) live in the Rhodope Mountains along the southern border with Greece and Turkey. Ethnic Turkish and Romani Muslims also live in large numbers in the northeast and along the Black Sea coast. Some recent Romani converts to Islam live in towns in the central region, such as Plovdiv and Pazardjik. According to the census, nearly 40 percent of Catholics live in and around Plovdiv. The majority of the small Jewish community lives in Sofia, Plovdiv, and along the Black Sea coast. Protestants are widely dispersed. Many Roma are Protestant converts, and Protestants are more numerous in areas with large Romani populations. Approximately 80 percent of the urban population and 62 percent of the rural population identifies as Orthodox Christian. Approximately 25 percent of the rural population identifies as Muslim, compared with four percent of the urban population.