Kloster Mariacron, Former monastery site in Oppenheim, Rhineland-Palatinate, Germany

Kloster Mariacron was a Benedictine, later Cistercian, convent outside Oppenheim's walls at Mainzerstraße 162. Most of it was demolished in the 19th century; the surviving gable wall and an inscription plaque on the street facade recall the site. The two-storey building with a salmon-pink stucco facade and a stepped gable relief stands on the former monastic grounds.

The monastery began as a Benedictine establishment before becoming a Cistercian convent for women. This shift reflects how religious practices evolved and adapted in medieval Germany.

The name Mariacron first appears in a document from 1280. The convent ran Oppenheim's first monastic school, teaching daughters of the noble castle men, and its abbesses held the right to nominate the priest of the Holy Spirit Hospital in Oppenheim. Abbess Margarethe Hilchen von Lorch (c. 1497–1518) donated a family tapestry now kept in the Cathedral and Diocesan Museum in Mainz.

The former monastery site is at Mainzerstraße 162, outside Oppenheim's old walls on the road to Mainz. Only a gable wall and an inscription plaque survive, so look for them on the street-side wall rather than expecting a courtyard complex. The neighbouring Nierstein parish house roof holds the monastery's 1645 bell.

The site's name survived through a brandy: in 1894 the Mariacron distillery was built on the former convent grounds, and after Eckes took it over in 1961 the label made the medieval name known worldwide. Production left Oppenheim in the 1980s.