Christianity in Ukraine dates back to the earliest centuries of the apostolic church and has remained the dominant religion in the country since its acceptance in 988 as the state religion. The majority of Ukranian Christians share a common Eastern Orthodox faith, while belonging to a number of different denominations.

Western Christian traditions, such as Roman Catholicism and Protestantism, have had a limited presence in Ukraine since at least the sixteenth century, but worshipers of these traditions remain a relatively small minority in today's Ukraine.

PCI's links with the Church in Ukraine are in Transcarpathia, in the West of the country, with members of the Transcarpathian Reformed Church or those belonging to congregations (where they exist) of the Hungarian Reformed Church.