The Greek Orthodox Church is a branch of Eastern Orthodox Christianity that is practiced primarily in Greece and other countries with significant Greek populations, such as Cyprus, Albania, and the Republic of Macedonia.

The Greek Orthodox Church is also present in other countries with smaller Greek communities, such as Australia, Canada, and the United States.

The Greek Orthodox Church is in full communion with other Eastern Orthodox churches. They recognize the Patriarch of Constantinople as their spiritual leader.

The Greek Orthodox Church has a distinct liturgy, which is based on the Byzantine Rite.