List of Bishops of Sion
List of bishops of the Roman Catholic Diocese of Sion:
Late Antiquity
;Bishops of Agaunum| From | To | Bishop | Notes |
| fl. 380s | Theodore | ||
| fl. 440 | Salvius/Silvius | ||
| fl. 490 | Prothais | ||
| 516 | Theodore II | ||
| 517 | Constantinus | ||
| 549 | Rufus | ||
| 565 | Agricola |
Early Middle Ages
| From | To | Bishop | Notes |
| 585 | Heliodorus | ||
| 613 | 614 | Leudemond | |
| 647 | 653 | Prothais | |
| 673 | 690 | Amatus | |
| 762 | 765 | Willicar | |
| 786/8 | 796/8 | Altheus | |
| fl. 805 | Theodore III | According to 12th-century legend, secular power was granted to the bishops of Sion by Charlemagne | |
| fl. 824 | Adalongus | ||
| 825 | 857 | Heyminus | |
| 877 | 899/900 | Waltherius | |
| 932 | Asmundus | ||
| fl. 940 | Manfredus | ||
| 983 | 984/5 | Amizo |
Prince-bishops of Sion
Middle Ages
Western Schism
;loyal to Avignon| From | To | Bishop | Notes |
| 1386 | 1386 | Guillaume of La Baume-Saint-Amourb | |
| 1387 | 1387 | Robert Chambrier | |
| 1388 | 1392 | Humbert de Billens | |
| 1398 | 1404 | Aymon Séchala | |
| 1404 | 1417 | Jacques de Challant |
;loyal to Rome
| From | To | Bishop | Notes |
| 1387 | 1388 | Gerardus | |
| 1392 | 1393 | Henri de Blanchis | |
| 1394 | 1402 | Guillaume IV of Rarogne | |
| 1402 | 1418 | Guillaume V of Rarogne | see Raron affair |
Renaissance to Early modern
| From | To | Bishop | Notes |
| 1418 | 1437 | André dei Benzi of Gualdo | Archbishop of Kolocza ; administrator from 1418, bishop from 1431. Valais witch trials. |
| 1437 | 1451 | Guillaume VI of Rarogne | |
| 1451 | 1457 | Henri Asperlin | |
| 1457 | 1482 | Walter Supersaxo | Burgundian War |
| 1482 | 1496 | Jost of Silenen | Member of Lucerne nobility and diplomat for the Swiss Confederacy, bishop of Grenoble 1477-1467, Jost ruled as a "Renaissance prince" but after failed campaigns against Milan was forced to abdicate and went into exile in Lyon, retaining only the title of titular bishop of Hierapolis. |
| 1496 | 1499 | Nicolas Schiner | |
| 1499 | 1522 | Mathieu Schiner | Cardinal; nephew of Nicolas Schiner |
| 1522 | 1528 | Philippe am Hengart Philippe de Platea | |
| 1529 | 1545 | Adrien I of Riedmatten | Valais becomes an eternal associate of the Old Swiss Confederacy in 1529. |
| 1548 | 1565 | Jean Jordan | |
| 1565 | 1604 | Hildebrand I of Riedmatten | |
| 1604 | 1613 | Adrien II of Riedmatten | |
| 1613 | 1638 | Hildebrand II Jost | In 1628, the Valais becomes a republic, but remains under the nominal rule of the prince-bishops. |
| 1638 | 1640 | Barthélemy Supersaxo | |
| 1640 | 1646 | Adrien III of Riedmatten | |
| 1646 | 1672 | Adrien IV of Riedmatten | |
| 1672 | 1701 | Adrien V of Riedmatten | |
| 1701 | 1734 | François-Joseph Supersaxo | |
| 1734 | 1752 | Jean-Joseph-Arnold Blatter | |
| 1752 | 1760 | Jean-Hildebrand Roten | |
| 1760 | 1780 | François-Joseph-Frédéric Ambuel | |
| 1780 | 1790 | François-Melchior-Joseph Zen-Ruffinen | |
| 1790 | 1807 | Joseph-Antoine Blatter | Last prince-bishop, loss of secular power with the French invasion of 1798. |
Modern history
| From | To | Bishop | Notes |
| 1807 | 1817 | Joseph-François-Xavier de Preux | |
| 1817 | 1829 | Auguste-Sulpice Zen-Ruffinen | |
| 1830 | 1843 | Maurice-Fabien Roten | |
| 1843 | 1875 | Pierre-Joseph de Preux | |
| 1875 | 1901 | Adrien VI Jardinier | |
| 1901 | 11 July 1918 | Jules-Maurice Abbet | Born 11 September 1845 |
| 1919 | 19 March 1952 | Victor Bieler | Born 16 March 1881 |
| 1952 | 1975 | François-Nestor Adam | Born 7 February 1903; died 8 February 1990 |
| 1975 | 1995 | Henri Schwery | Born 14 June 1932 |
| 1995 | 2014 | Norbert Brunner | Born 21 June 1942 |
| 2014 | Jean-Marie Lovey | Born 2 August 1950 |