In simplistic terms, the Ukrainian Catholic Church, also known as the Ukrainian Greek Catholic Church, is a part of the Catholic Church that observes the same traditions as does Eastern Orthodoxy. It is, however, very much part of the Catholic Church. The current head of the Universal Catholic Church, and hence the Ukrainian Catholic Church, is Pope Francis.

The Ukrainian Catholic Church world-wide is governed internally by the Synod of Ukrainian Catholic Bishops. Its highest ranking cleric is Patriarch (Major Archbishop) Sviatoslav Shevchuk, and the regional leader of Ukrainian Catholics in New England and the State of New York is Eparch (Bishop) Paul Chomnycky, O.B.S.M., of the Eparchy (Diocese) of Stamford, Connecticut.

Many people do not know the Catholic Church consists of over twenty churches. The largest by population is the Roman Catholic Church. The non-Roman Catholic Churches fit into one of six liturgical traditions: Alexandrian, Antiochene (or Syrian), Armenian, Byzantine, Maronite, and Chaldean. The Ukrainian Catholic Church follows the Byzantine tradition, and traces its origins to the Union of Brest in 1596 A.D., when the Church in Kyiv entered into communion with Rome.

Differences between Ukrainian Catholicism and Roman Catholicism range from minor to significant. Ukrainian Catholics cross themselves from right to left, not left to right; Holy Communion is always distributed directly into the mouths of communicants by a priest using a spoon; and married Ukrainian Catholic men can be ordained as priests or deacons. However, unmarried clergy may not marry and widowed clergy may not remarry.

Ukrainian Catholics celebrate their faith with the Divine Liturgies of St. John Chrysostom and St. Basil the Great, which are quite different from the Roman Catholic Liturgy as reformed by the Second Vatican Council. Roman Catholics may also notice the absence of the Filioque ("and the Son") during the Profession of Faith. All Eastern Catholic Churches use the original version of the Creed of the Council of Nicea without the added words.

Outside of the U.S. and western Canada, many Ukrainian Catholics, especially those in Ukraine, follow the Julian ("Old") Calendar as opposed to the Gregorian ("New") Calendar. The latter is used by the Western Churches—Catholic and Protestant—and in all civil societies.

In these ways and others, Ukrainian Catholics may seem more Eastern Orthodox than Roman Catholic. However, all Catholics, regardless of their liturgical tradition, may receive Holy Communion in Ukrainian Catholic churches.