The Ukrainian Catholic Church was formed in the Church Union of Berestia (1596); until the 1960s it was known as the Greek Catholic Church. The Ukrainian Catholic Church was one of the dominant churches in the Western Ukrainian territories that did not come under Russian or Soviet rule until 1939. The Church gave allegiance to the Pope and to Rome but at the same time maintained traditional Eastern religious customs of the Byzantine rite.

The Church was officially liquidated in 1946, with the re-occupation of Western Ukraine and its re-incorporation into the USSR. Clergy and faithful who refused to convert to Russian orthodoxy were severely persecuted; most of the Church hierarchy died in concentration camps. Metropolitan Josyph Slipyj was released from prison in 1963 and permitted to emigrate. The Church survived in the underground and the diaspora; Poland and Canada had the largest numbers of faithful.

In the USSR, secret services continued to be held, and priests and bishops continued to be ordained in the underground. With the liberalization of the 1980s, the Ukrainian Catholic Church re-emerged in public and demanded legalization. This movement, supported by the Vatican, quickly gained momentum, and the Church was given official permission to register by the Council for Religious Affairs of the Ukrainian SSR in December 1989, and parishes were established throughout Western Ukraine. There are currently between three and five million members of the Church in Ukraine.