Southern Ukraine
According to a 2016 survey of religion in Ukraine conducted by the Razumkov Center, around 65.7% of the population of southern Ukraine declared to be believers in any religion, while 7.4% declared to be non-believers, and 3.2% declared to be atheists and agnostics. the study also found that 77.6% of the total Southern Ukraine population declared to be Christians (71.0% Eastern Orthodox, 5.1% simply Christians, 0.5% Latin Rite Catholics, 0.53% members of various Protestant churches, 0.5% members of the Ukrainian Greek Catholic Church), and 0.5% were Jewish. Not religious and other believers not identifying with any of the listed major religious institutions constituted about 24.7% of the population.
Wołyń Voivodeship (1921–1939)
The primary religions practised in the area were Eastern Orthodox Christian (69.8%), Roman Catholic (15.7%) as well Judaism by the Jews (10%), Protestantism (2.6%) and the Islamic faith by the Tatars. With respect to the Orthodox Ukrainian population in eastern Poland, the Polish government initially issued a decree defending the rights of the Orthodox minorities. In practice, this often failed, as the Catholics, also eager to strengthen their position, had official representation in the Sejm and the courts. With time, some 190 Orthodox churches were destroyed or disassembled (many of them already abandoned), and 150 more were transformed into Roman Catholic churches. Such actions were condemned by the head of the Ukrainian Greek Catholic Church, metropolitan Andrei Sheptytsky, who claimed that these acts would "destroy in the souls of our non-united Orthodox brothers the very thought of any possible reunion."