Prieuré de Marast, Romanesque priory church in Marast, France

Prieuré de Marast is a former Augustinian priory whose Romanesque church, built in the 1120s–1130s, has a plain west facade with three windows set in a triangle above the unadorned portal. The nave has eight bays with round-arched arcades on alternating square and round pillars, and the choir ends in a five-sided apse. The conventual buildings face the Grande Cour.

Founded in 1117 by donations from Richard de Montfaucon, Count of Montbéliard, and Thiébaud de Rougemont on their Esprels lands, the priory depended on Chaumousey Abbey. Archbishop Anseric of Besançon confirmed it in 1122 and Pope Calixte II in 1123. The priors held the right of lodging in nearby villages such as Chassey-lès-Montbozon. The last resident canon died in 1747, ending religious life.

The church was first placed under the name of the Virgin Mary, then became known as the church of Sainte-Marie-Madeleine de Marast from the 13th century, following a local devotion to Saint Mary Magdalene. The priory opens for religious services only once a year, for the Mass of Saint Mary Magdalene, an important parish event in the area.

The church is open to visitors and features facilities for people with reduced mobility. A scale model of the entire complex provides a helpful overview of how the original site was structured.

The Villersexel chapel, described as ruined in the 18th century, held tombs later moved into the choir. Among them are Isabeau de Mailly, who died on 28 May 1253, her son Aymon de Villersexel, who died on 18 December 1309, his wife Guillemette de Ray, who died in 1270, and Jean de Faucogney, who died on 27 March 1319.