The U.S. government estimates the total population at 9.6 million (July 2017 estimate). According to a January 2016 survey by the state Information and Analytical Center of the Presidential Administration, approximately 53 percent of the adult population belongs to the BOC and 6 percent to the Roman Catholic Church. Eight percent of the adult population is atheist, and 22 percent is uncertain. Smaller religious groups together constituting approximately 2 percent of the population include Jews; Muslims; Greek Catholics (“Uniates”); Old Believers (both those who practice their faith with priests, usually termed “priestist,” and those who practice their faith without priests, usually termed “priestless”); and other Orthodox groups in addition to the BOC. This 2 percent also includes Lutherans, Jehovah’s Witnesses, Apostolic Christians, Presbyterians and other Protestant groups, Armenian Apostolics, Latin Catholics, ISKON, Bahais, members of The Church of Jesus Christ of Latter-day Saints (Mormons), and Buddhists. Jewish groups state there are between 30,000 and 40,000 Jews. Ethnic Poles, who constitute approximately 3 percent of the population, tend to be Roman Catholic.

The U.S. government estimates the population at 142.2 million (July 2017 estimate). The most recent figures from a 2015-2016 poll by the Pew Research Center report 71 percent of the population consider themselves Orthodox, while 10 percent identify as Muslim. Religious groups constituting less than 5 percent of the population each include Buddhists, Protestants, Roman Catholics, Jews, members of The Church of Christ of Latter-day Saints (Mormons), Jehovah’s Witnesses, Hindus, Bahais, members of the International Society of Krishna Consciousness (ISKCON), pagans, Tengrists, Scientologists, and Falun Gong adherents. The 2010 census estimates the number of Jews at 150,000; however, the president of the Federation of Jewish Communities (FEOR) stated in February 2015 the actual Jewish population is nearly one million, most of whom live in Moscow and St. Petersburg. Immigrants and migrant workers from Central Asia are mostly Muslim. The majority of Muslims live in the Volga Ural region and the North Caucasus. Moscow, St. Petersburg, and parts of Siberia also have sizable Muslim populations.

The U.S. government estimates the population at 7.1 million (July 2017 estimate). According to the 2011 census, approximately 85 percent of the population is Orthodox Christian, 5 percent Roman Catholic, 3 percent Sunni Muslim, and 1 percent Protestant. The remaining 6 percent includes Jews, Buddhists, members of the International Society of Krishna Consciousness, agnostics, atheists, other religious groups, and individuals without a declared religious affiliation. The vast majority of the population identifying as Orthodox Christian are members of the Serbian Orthodox Church (SOC), a category not specifically listed in the census. Adherents of the Macedonian, Montenegrin, and Romanian Orthodox Churches may be included in the numbers of “Orthodox Christians” or in the “other Christian” category that is part of the remaining 6 percent, depending on how they self-identify.

Catholics are predominantly ethnic Hungarians and Croats residing in Vojvodina Province. Muslims include Bosniaks (Slavic Muslims) in the southwest Sandzak region, ethnic Albanians in the south, and Roma located throughout the country.