正教会（希腊语：Ορθόδοξη Εκκλησία，orthódoxi ekklisía；俄语：Православная Церковь，罗马化：pravoslavnaja tserkovʹ），也称为东正教会，简称东正教，与天主教会及新教并列为基督教三大教派，信徒总人数少于天主教，但比新教最大的普世圣公宗要多出两倍，主要分布在巴尔干半岛、东欧和西亚。

基督教的教派以教会区分，例如：天主教会，正教会，新教会，它们不是个别独立的宗教，所以不能称为天主教，东正教，新教。 它们全都是基督教(chritianity)

The Eastern Orthodox Church, officially the Orthodox Catholic Church, also referred to as the Orthodox Church, Eastern Orthodoxy, and Orthodoxy, is the second largest Christian Church in the world, with an estimated 225–300 million adherents.

The Eastern Orthodox Church is one of the oldest religious institutions in the world, teaching that it is the One, Holy, Catholic and Apostolic Church established by Jesus Christ in his Great Commission to the apostles, and practicing what it understands to be the original faith passed down from the Apostles.