Abbey of Saint-Martin, Pontoise, Medieval Benedictine abbey in Pontoise, France

The Abbey of Saint-Martin in Pontoise was a Benedictine monastery founded in the 11th century. Most buildings were demolished from 1791; only the 12th-century bell tower of the abbey church and a 15th-century barn remain. The estate now houses the Saint-Martin-de-France School, run by Oratorians.

The monastery was founded in the first half of the 11th century and became important after its first abbot, Walter, was declared a saint. This made it a significant pilgrimage destination.

The abbey's name comes from its move in 1080 to the parish church of the bourg Saint-Martin, first called Saint-Germain-et-Saint-Martin. A winter fair and market of Saint-Martin was held for eight days on the tree-lined square outside the gate. The tomb of Saint Walter, now in the Notre-Dame church, was long the focus of pilgrimage.

The estate now houses the Saint-Martin-de-France School, run by the Oratorians. Of the monastic buildings, only the 12th-century bell tower of the abbey church, listed as a monument, and a 15th-century barn survive; the rest was razed from 1791. The abbey's archives are held at the Val-d'Oise departmental archives.

The carved tomb effigy of Saint Walter, classified as a Monument historique, was moved to the Notre-Dame church in Pontoise during the Revolution. It shows his upper body in layered robes, a staff across the chest and a hand gripping a rounded object; a lower panel carries interlaced lines and circles forming a star-like design.