The Pontifical Academy of Sciences is a scientific academy of the Vatican City, established in 1936 by Pope Pius XI. Its aim is to promote the progress of the mathematical, physical, and natural sciences and the study of related epistemological problems. The Accademia Pontificia dei Nuovi Lincei was founded in 1847 as a more closely supervised successor to the Accademia dei Lincei established in Rome in 1603 by the learned Roman Prince, Federico Cesi (1585–1630), who was a young botanist and naturalist, and which claimed Galileo Galilei as its president. The Accademia dei Lincei survives as a wholly separate institution.

Pope Pius XI, born Ambrogio Damiano Achille Ratti, was the Bishop of Rome and supreme pontiff of the Catholic Church from 6 February 1922 to 10 February 1939. He also became the first sovereign of the Vatican City State upon its creation as an independent state on 11 February 1929. He remained head of the Catholic Church until his death in February 1939. His papal motto was "Pax Christi in Regno Christi", translated as "The Peace of Christ in the Reign of Christ".