Providentissimus Deus (translated as "On the Study of Holy Scripture"), was a the title given to a papal letter issued on issued on 18 November 1893 by Pope Leo XIII.

The letter reflects the Catholic Churches official late nineteenth century position on the study of scripture and rational criticism of religion, outlining how religious teaching and scientific thought should be considered separately and therefore as non-contradictory.. 

Providentissimus Deus refers to apparent contradictions between the Bible and physical science, and encourages theologians to educate themselves in the theories of rational or scientific thought, so as to be better able to defend religious theology.