This article contains a list of encyclicals of Pope Pius XI. Pius XI issued 31 papal encyclicals during his reign as pope and was considering one at his death.
No. Title (Latin, except where is noted) Title (English translation) Subject Date1. Ubi arcano Dei consilio "The Hidden Counsel of God" "On the Peace of Christ in His Kingdom" 23 December 19222. Rerum omnium perturbationem "Disturbance of All Things" On St. Francis De Sales 26 January 19233. Studiorum ducem "The Guide in Studies" On St. Thomas Aquinas 29 June 19234. Ecclesiam Dei "The Church of God" On St. Josaphat Kuntsevych 12 November 19235. Maximam gravissimamque "The Greatest and Gravest" On French Diocesan Association 18 January 19246. Quas primas "In The First" On the Feast of Christ the King 11 December 19257. Rerum Ecclesiae "Of the Things of the Church" Catholic Missions 28 February 19268. Rite expiatis " " On St. Francis of Assisi 13 April 19269. Iniquis afflictisque "Unequal and Afflicted" On the Persecution of the Church in Mexico 18 November 192610. Mortalium animos "The Minds of Mortals" On Religious Unity 6 January 192811. Miserentissimus Redemptor "Most Merciful Redeemer" Reparation to the Sacred Heart 8 May 192812. Rerum orientalium "Of Eastern Things" Promoting Oriental Studies 8 September 192813. Divini cultus "Of Divine Worship" On Divine Worship 20 December 192814. Mens nostra "Our Mind" Promotion of the Spiritual Exercises 20 December 192915. Divini illius Magistri "That Divine Teacher" On Christian Education 31 December 192916. Quinquagesimo ante "Fifty Years Ago" On His Priestly Jubilee 23 December 192917. Ad salutem "For Salvation" On St. Augustine 30 April 193018. Casti connubii "Chaste Wedlock" On Christian marriage 31 December 193019. Quadragesimo anno "In the Fortieth Year" On the Reconstruction of the Social Order 15 May 193120. Non abbiamo bisogno (in Italian) "We Do Not Need" Catholic Action in Italy 29 June 193121. Nova impendet "A New Scourge Threatens" On the Economic Crisis 2 October 193122. Lux veritatis "The Light of Truth" On the Council of Ephesus 25 December 193123. Caritate Christi compulsi "The Love of Christ Impels Us" On the Sacred Heart 3 May 193224. Acerba animi "Sorrow of Soul" On the Persecution of the Church in Mexico 29 September 193225. Dilectissima Nobis "Most Dear to Us" On the Persecution of the Church in Spain 3 June 193326. Ad Catholici sacerdotii "To the Summit of Catholic priesthood" On the Catholic priesthood 20 December 193527. Vigilanti cura "Vigilant Care" On Motion Pictures 29 June 193628. Mit brennender Sorge (in German) "With Burning Anxiety" On the Church and the German Reich 14 March 193729. Divini Redemptoris "Of a Divine Redeemer" On Atheistic Communism 19 March 193730. Nos es muy conocida (in Spanish) "It Is Well Known to Us" On the Religious Situation in Mexico 28 March 193731. Ingravescentibus malis "The Increasing Evils" On the Rosary 29 September 1937
At the time of his death, Pius XI was reviewing an early version of an additional encyclical, Humani generis unitas (On the Unity of the Human Race), on the church, anti-Semitism, racism, and persecution of Jews.