Orthodox Christians are divided between the Eastern Orthodox Church and Oriental Orthodoxy. The Eastern Orthodox Church is the second largest communion in the world after the Roman Catholic Church. The Oriental Orthodoxy have close beliefs but practice separate religious rites with the Oriental Orthodoxy being more diverse than the conservative Eastern Orthodox Church. Eastern Orthodoxy is dominant in Belarus, Bulgaria, Cyprus, Georgia, Greece, Macedonia, Moldova, Montenegro, Romania, Russia, Serbia, and Ukraine while Oriental Orthodoxy is evident in Armenia, Ethiopia, and Eritrea.
10. Georgia (3.8 million)
The Georgian Apostolic Autocephalous Orthodox Christians number nearly 3.8 million. They belong to the Eastern Orthodox Church. The Georgian Orthodox population is the highest in the country and is governed by the Holy Synod of Bishops. The current Georgian constitution recognizes the church’s role but specifies its independence from the state. This stands in contrast to the country's history pre-1921, when it was the official state religion.
9. Egypt (3.9 million)
The majority of Christians in Egypt are members of the Oriental Orthodox Church, constituting about 3.9 million believers. The largest denomination of the church is Coptic Orthodox of Alexandria followed by Armenian and Syriac Orthodoxies. The church in Egypt was founded by Saint Mark, an apostle and evangelist, in the year 42 AD.
8. Belarus (5.9 million)
Belarus Orthodox Christians are part of the Eastern Orthodoxy and number close to 6 million in the country. The Christians are in full communion with their counterparts in the Russian Orthodox Church and are the largest denomination in Belarus.
7. Bulgaria (6.2 million)
The Bulgarian Orthodox Christians number about 6.2 million independent Ecumenical Patriarchate Eastern Orthodox believers. The Bulgarian Orthodox Christians are the oldest in the Slavic region, dating back to the 5th century Bulgarian Empire. The Orthodoxy also forms the largest religion in Bulgaria.
6. Serbia (6.7 million)
The autonomous Serbian Orthodox Church, a member of the autocephalous Eastern Orthodox Christianity, is the leading Serbian religion with close to 6.7 million members representing 85% of the population. This is more than most ethnic groups in the country combined. There are a few Romanian Orthodox Christians in parts of Serbia established by migrant communities. Most Serbians identify themselves with the Orthodox Church and not by ethnicity.
5. Greece (10 million)
Christians who profess the Orthodox doctrine form close to 10 million of the population in Greece. The Greek Orthodox Church comprises of several Orthodox denominations in communion with the larger Eastern Orthodoxy conducting liturgy in the original language of the New Testament, Koine Greek. Greek Orthodox Christians strictly follow the Byzantine Empire Church traditions.
4. Romania (19 million)
The majority of the 19 million Romanian Orthodox Christians are part of the autocephalous Eastern Orthodox Christian population.The number represents approximately 87% of the population making the Romanian language occasionally called the Ortodoxie. Romanian Orthodox Christians were canonically recognized in 1885 and observe strict Orthodox hierarchy that has existed for centuries.
3. Ukraine (35 million)
Ukraine has approximately 35 million members of the Orthodox Christian population. The Ukrainian Orthodox Church became independent from Russian Orthodox Church after the fall of the USSR. The Ukrainian church is in communion with the Eastern Orthodoxy and is the largest religious population in the country, representing 75% of the total population. Few other branches are still under the Moscow Patriarch, but Ukrainian Christians are largely unaware of which denominations they belong to. Orthodoxy in Ukraine has apostolic roots and has been declared a state religion several times in the past.
2. Ethiopia (36 million)
In Ethiopia, the Ethiopian Orthodox Tewahedo Church is the largest and oldest church by both population and structure. The 36 million Ethiopian Orthodox Christians are in communion with Oriental Orthodoxy and were part of the Coptic Orthodox Church until 1959. Ethiopian Orthodox Christians are independent and the largest of all Oriental Orthodoxies.
1. Russia (101 million)
Russia has the highest number of Orthodox Christians in the entire world totaling close to 101 million people. The Church, also known as the Moscow Patriarchate, is an autocephalous Eastern Orthodoxy in full communion with the Eastern Orthodox Church body. Russia is perceived to be intolerant of Christians, and the figure of Orthodox Christians has been disputed over time. A small number of Russians believe in God or even profess the Orthodox faith. Many citizens call themselves Orthodox Christians because they were baptized in the church as children or listed it in official government records but do not practice the religion.