Longpont Abbey (Abbaye Notre-Dame de Longpont) was a Cistercian monastery, in present-day Longpont, Aisne, France.

It existed from 1131 to 1793, being founded by monks from the abbey of Clairvaux, at the behest of Jocelin of Soissons. There is now a hotel on the site, located in the old Cistercian inn. The roofless abbey church can be visited, along with the better-preserved buildings around the cloister. The original buildings suffered war damage in 1918.

Its monks included Petrus Cantor and John de Montmirail.

• Raoul II, Count of Vermandois
• Eleanor, Countess of Vermandois
• Jean de Montmirail

• Pickard, Charlotte (2015) "Unequal Marriage in Medieval France: The Case of the Vermandois Heiresses" DOI: 10.6084/m9.figshare.4286954.v1
• Poquet, Monographie de l'abbaye de Longpont (Paris: 1869)

• (in French) [1]
• (in French) [2]
• (in French) [3]
• [4]

49°16′23″N 3°13′16″E / 49.273°N 3.221°E / 49.273; 3.221