Pope Pius X issued 17 papal encyclicals during his reign as Pope:
| No. | Title (Latin) | Title (English translation) | Subject | Date | Text |
|---|---|---|---|---|---|
| 1. | E supremi | "On high" | On the Restoration of All things in Christ | 4 October 1903 | [1] |
| 2. | Ad diem illum laetissimum | "On that most happy day" | On the Immaculate Conception | 2 February 1904 | [2] |
| 3. | Iucunda sane | On Pope Gregory the Great | 12 March 1904 | [3] | |
| 4. | Acerbo nimis | "At This Extremely Harsh (Time)" | On Teaching Christian Doctrine | 15 April 1905 | [4] |
| 5. | Il fermo proposito | On Catholic Action in Italy | 11 June 1905 | [5] | |
| 6. | Vehementer Nos | "We with vehemence" | On the French Law of Separation | 11 February 1906 | [6] |
| 7. | Tribus circiter | "Circumscribed tribes" | On the Mariavites: Mystic Priests of Poland | 5 April 1906 | [7] |
| 8. | Pieni l'animo | On the Clergy in Italy | 28 July 1906 | [8] | |
| 9. | Gravissimo officii munere | On French Associations of Worship | 10 August 1906 | [9] | |
| 10. | Une fois encore | On the Separation of Church and State | 6 January 1907 | [10] | |
| 11. | Pascendi dominici gregis | "The Feedings of the Flock of the Lord" | On the Doctrine of the Modernists | 8 September 1907 | [11] |
| 12. | Communium rerum | "Of Common Things" | On St. Anselm of Aosta | 21 April 1909 | [12] |
| 13. | Editae saepe | On St. Charles Borromeo | 26 May 1910 | [13] | |
| 14. | Notre charge apostolique | “Our Apostolic Mandate” | On socialist doctrines of the Sillon movement | 15 August 1910 | [14] |
| 15. | Iamdudum | "Long since" | On the Law of Separation in Portugal | 24 May 1911 | [15] |
| 16. | Lacrimabili statu | "In a tearful state" | On the Indians of South America | 7 June 1912 | [16] |
| 17. | Singulari quadam | On Labour Organisations | 24 September 1912 | [17] |