Weissemburg Abbey (German: Kloster Weißenburg, French: L'abbaye de Wissembourg), also Wissembourg Abbey, is a former Benedictine abbey (1524–1789: collegiate church) in Wissembourg in Alsace, France.

Weissenburg Abbey was founded in 661 by the Bishop of Speyer, Dragobodo. The name Wissembourg is a Gallicized version of Weißenburg (Weissenburg) in German meaning "white castle".

Thanks to donations from the nobility and local landowners the monastery quickly acquired possessions and estates in the Alsace, Electorate of the Palatinate and in the west-Rhine county of Ufgau. As a result, manorial farms and peasant farmsteads were set up and agriculture system introduced to create fertile arable farmland.

Around 1100, it was important for the monastery, which had now become wealthy, to distance itself from the Bishop of Speyer and his influence. To this end a new tradition was established about the origins of the monastery, backed up by forged documents (such forgery was not anything unusual in the Middle Ages). In the case of Weissenburg, the story now ran that the abbey had been founded in 623 by the Merovingian king, Dagobert I. Detailed historic research in recent decades has demonstrated that this was unlikely to have been the case.

Weissenburg developed quickly into one of the wealthiest and culturally most significant abbeys in Germany. As early as 682 it was able to purchase shares in a saltworks in Vic-sur-Seille for the princely sum of 500 solidi; in 760 it was given the Mundat Forest. The Gospel Book (Evangelienbuch) written around 860 by a monk, Otfrid of Weissenburg, represented a milestone in the development of German language and literature. it is the first poem to employ rhyme instead of the old Germanic alliteration, though the rhyme is still very imperfect, being often mere assonance, with frequent traces of alliteration.

At that time the abbey was in the charge of Abbot Grimald of Weissenburg, who was also the Abbot of the Abbey of Saint Gall and chancellor to Emperor Louis the German, and thus was one of the most important figures in the whole of the German imperial church.

The abbey lost an important possession, however, when in 985 the Salian Duke Otto appropriated 68 of the parishes belonging to it in the so-called Salian Church Robbery (Salischer Kirchenraub). Above all though, it was the transition from a situation in which the abbey managed its monastic estates itself to a feudal system in which the estates were granted as fiefs, that resulted in the loss of most of the abbey's possessions. This was because, over time, their vassal viewed their fiefs as allods, i.e. as freehold properties. Thus the once extensive monastic estates increasingly evaporated. In the 16th century only three estates were left out of the thousands the abbey used to possess: these were Steinfeld, Schweighofen and Koppelhof; in addition, the abbey had tithe rights in Weissenburg and Bergzabern which gave it an annual income of 1,500 gulden.

In 1262–1293, during the time of its decline, Abbot Edelin (d. 15 October 1293) attempted to halt the loss of the monastic estates and to recover its stolen property by compiling a record of the abbey's possessions in a new register. This index, called the Codex Edelini or Liber Possessionum, is currently held in the Speyer State Archives (Landesarchiv Speyer). Edelin is credited with building the Gothic abbey church, which still stands today. The church incorporated a Romanesque bell tower, the sole remains of the earlier church built in the 11th century under the direction of abbot Samuel. (The church is on the Route Romane d'Alsace.) He also oversaw the construction of a refectory and subterranean furnaces to warm the monastery.