Saint Maria Faustyna Kowalska of the Blessed Sacrament, O.L.M., popularly spelled as Sister Faustina (born as Helena Kowalska, 25 August 1905 in Glogowiec – 5 October 1938 in Kraków, Poland), was a Polish religious, Christian mystic, and nun. Her claims of receiving apparitions of Jesus Christ inspired the Roman Catholic devotion known as the Divine Mercy.