de Oelenberg; French: Abbaye Notre-Dame d'Oelenberg; Alemannic German: Kloschter vum Eelabarg) is a Trappist monastery located in Reiningue near Mulhouse, France.

It has been an important place of worship in Alsace since the 11th century and most recently hosted a small community of ten monks (as of 2024).

[1] The former Augustinian then Jesuit church with its nave, its two-level transept, its choir and its burial vault were listed as a Historic Monument on June 16, 1992.

[2] In 1046, a priory of the Canons Regular of St. Augustine was founded by Heilwig of Dabo, Countess of Eguisheim and mother of Pope Leo IX.

In the August of 1845 and June 1846, the Polish romantic poet Józef Bohdan Zaleski spent some time on spiritual retreats in the abbey.

The French artillery wanted to spare the monastery, but had to bomb an observatory built by the Germans in the bell tower of the church.

The life at Oelenberg is led by the Ora et labora ("Pray and work") practice of the Rule of Benedict interpreted by the Cistercian tradition.