| Saint-Thierry Abbey | |
| Native Name: | l'Abbaye du Mont d'Hor |
| Native Name Lang: | fr |
| Order: | Benedictines |
| Denomination: | Catholic Church |
| Dedication: | Saint Thierry |
| Archdiocese: | Reims |
| Abbess: | --> |
| Prioress: | --> |
| Heritage Designation: | Classé MH 1926–1932 |
| Location: | Saint-Thierry, Marne, Champagne-Ardenne |
| Country: | France |
| Map Type: | France |
| Map Relief: | y |
| Coordinates: | 49.3047°N 3.9655°W |
Saint-Thierry Abbey (French: Abbaye de Saint-Thierry) was formerly a Benedictine abbey in the village of Saint-Thierry, Marne,It was closed in the 17th century and razed to the ground during the French Revolution.Since 1968 it has been a Benedictine nunnery in the Archdiocese of Reims.
The abbey was founded by Theodoric of Mont d'Hor around 500 and dedicated to Saint Bartholomew the Apostle.This men's abbey became Benedictine around 974 and Adalbero of Reims had Thierry's relics transferred to the monastery. The cult of Thierry supplanted that of Bartholomew in the long term.
It became a monastery of the Congregation of Saint Maur from 1627/1628 until its suppression. It was abolished on 2 April 1695 by King Louis XIV.This was to compensate for the damage that the Church of Reims suffered during the creation of the Archdiocese of Cambrai. This extinction was ratified by a papal bull of Pope Innocent XII dated 13 September 1696, and it became the secondary residence of the archbishops of Reims. In 1777 the community was driven out and the abbey completely razed; the community being relocated for a time to Reims. Only the chapter house, dating from the 12th century, remained standing.
Bernard de Montfaucon made an inventory of the books of the abbey in his Bibliotheca bibliecarum manuscriptorum nova, Paris, 1739, and there are still nearly 150, mostly in the Municipal Library of Reims as well as a few copies in the Vatican Library and the Bibliothèque nationale de France
After two centuries of interruption, monastic life resumed on the hill of Saint-Thierry when the Benedictines of the Vanves congregation arrived in 1968. The long tradition of prayer, hospitality and work began to be reborn.