The Slovak Greek Catholic Church, or Slovak Byzantine Catholic Church, is a Byzantine Rite particular Church in full union with the Roman Catholic Church. L'Osservatore Romano of January 31, 2008 reported that, in the Slovak Republic alone, it had some 350,000 faithful, 374 priests and 254 parishes. In addition, the 2007 Annuario Pontificio gave its Canadian Eparchy of Saints Cyril and Methodius of Toronto as having 25,000 faithful, 6 priests and 7 parishes. The Slovak Greek Catholic Church is in full communion with Holy See.
Since the Union of Uzhhorod in 1646 was unanimously accepted on the territory that includes present day eastern Slovakia, the history of Slovak Greek Catholic Church was for centuries intertwined with that of the Ruthenian Catholic Church. At the end of World War I, most Greek Catholic Ruthenians and Slovaks were included within the territory of Czechoslovakia, including two eparchies, Prešov and Mukačevo. The eparchy of Prešov, created on September 22, 1818, was removed in 1937 from the jurisdiction of the Hungarian primate and subjected directly to the Holy See, while the 21 parishes of the eparchy of Prešov that were in Hungary were formed into the new exarchate of Miskolc.
After World War II, the eparchy of Mukačevo in Transcarpathia was annexed by the Soviet Union, thus the eparchy of Prešov included all the Greek Catholics that remained in Czechoslovakia. After communists seized the country in April 1950, a "synod" was convoked at Prešov, at which five priests and a number of laymen signed a document declaring that the union with Rome was disbanded and asking to be received into the jurisdiction of the Moscow Patriarchate, later the Orthodox Church of Czechoslovakia. Greek Catholic bishop Blessed Pavel Petro Gojdič of Prešov along with his auxiliary, Blessed Basil Hopko, were imprisoned and bishop Gojdič died in prison in 1960.
During the Prague Spring in 1968, the former Greek Catholic parishes were allowed to restore communion with Rome. Of the 292 parishes involved, 205 voted in favor. This was one of the few reforms by Dubček that survived the Soviet invasion the same year. However, most of their church buildings remained in the hands of Orthodox Church.
After communism was overthrown in the 1989 Velvet Revolution, most of the Church property was returned to the Slovak Greek Catholic Church by 1993, the year after the dissolution of Czechoslovakia into the Czech Republic and Slovakia. For Greek Catholics in the Czech Republic, a separate Apostolic Vicariate was created, elevated in 1996 to an Exarchate; the 2007 Annuario Pontificio indicated that it had by then grown to having 177,704 faithful, 37 priests and 25 parishes.
In Slovakia itself, Pope John Paul II created an Apostolic Exarchate of Košice in 1997. Pope Benedict XVI raised this to the level of an Eparchy on January 30, 2008 and at the same time erected the new Byzantine-rite Eparchy of Bratislava. He also raised Prešov to the level of a metropolitan see, constituting the Slovak Greek Catholic Church as a sui iuris metropolitan Church. At that date there were only two other sui iuris metropolitan Eastern Catholic Churches: the Ethiopian Catholic Church and the Ruthenian Metropolia of Pittsburgh.