|Bishop of Rome|
|Church||Catholic Church, Orthodox Church|
|Papacy began||c. 115|
|Papacy ended||c. 124|
|Died||125 (aged c. 82 – 83)|
Rome, Roman Empire
|Feast day||6 April|
|Title as Saint||Martyr|
|Other popes named Sixtus|
Pope Sixtus I (42 – 124/126/128), also spelled Xystus, a Roman of Greek descent, was the bishop of Rome from c. 115 to his death. He succeeded Pope Alexander I and was in turn succeeded by Pope Telesphorus. His feast is celebrated on 6 April.
The oldest documents[which?] use the spelling Xystus (from the Greek ξυστός, xystos, "shaved") in reference to the first three popes of that name. Pope Sixtus I was also the sixth Pope after Peter, leading to questions as to whether the name "Sixtus" is derived from sextus, Latin for "sixth".
The "Xystus" mentioned in the Catholic Canon of the Mass is Xystus II, not Xystus I.
The Holy See's Annuario Pontificio (2012) identifies him as a Roman by birth, who served from 117 or 119 to 126 or 128. His father's name was Pastor.
According to the Liberian Catalogue of popes, he served the Church during the reign of Hadrian "from the consulate of Niger and Apronianus until that of Verus III and Ambibulus", that is, from 117 to 126. Eusebius states in his Chronicon that Sixtus I reigned from 114 to 124, while his Historia Ecclesiastica, using a different catalogue of popes, claims his rule from 114 to 128. All authorities agree that he reigned about ten years.
Like most of his predecessors, Sixtus I was believed to have been buried near Peter's grave on Vatican Hill, although there are differing traditions concerning where his body lies today. In Alife, there is a Romanesque crypt, which houses the relics of Pope Sixtus I, brought there by Rainulf III. Alban Butler (Lives of the Saints, 6 April) states that Clement X gave some of his relics to Cardinal de Retz, who placed them in the Abbey of Saint Michael in Lorraine.
Sixtus I instituted several Catholic liturgical and administrative traditions. According to the Liber Pontificalis (ed. Duchesne, I.128), he passed the following three ordinances: