Abbaye de Saint-Jean-aux-Bois, Medieval abbey in Saint-Jean-aux-Bois, France

Abbaye de Saint-Jean-aux-Bois is a former Benedictine abbey in the forest of Compiègne, in the Oise department of Hauts-de-France. Its Gothic church, built in the 1220s, has a tall pitched roof of reddish-brown tiles, buttressed light-stone walls, and pointed-arch windows; inside, pale columns line a narrow room with wooden benches and a stained-glass window above the altar. The chapter house, fortified gate, and part of the enclosure wall survive.

Founded in 1152 by Queen Adelaide of Savoy, widow of Louis VI, who bought the former royal house of Cuise to install Benedictine nuns under the Cluny rule. The chapter house dates from the 1160s–1170s, but the abbey church was only begun in the 1220s. In 1634 the nuns exchanged the isolated site with Augustinian canons, and the priory was suppressed on 25 June 1761.

The abbey's name comes from Saint John the Baptist, whom early papal bulls call its patron, and from the forest of Cuise. The nuns kept a relic of Saint Euphrosyne of Alexandria, taken from a reliquary convoy travelling to Reims that they hosted overnight. The parish church still serves the village today.

The church and chapter house are open for visitors to explore on their own, with the main entrance on the south side providing access to these key areas. Visitors can walk through the vaulted spaces and see how monks and nuns once moved through these rooms daily.

The abbey's archives were destroyed during the Revolution, so almost nothing is known about daily life in the Benedictine community. What survives is the fortified gate on rue des Plaideurs and part of the enclosure wall, which still mark the old monastic precinct in the village.