| Montigny-Lengrain | |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason ville fr Montigny-Lengrain.svg |
| Arrondissement: | Soissons |
| Canton: | Vic-sur-Aisne |
| Insee: | 02514 |
| Postal Code: | 02290 |
| Mayor: | Chantal Mouny[1] |
| Term: | 2020 - 2026 |
| Coordinates: | 49.3722°N 3.1°W |
| Elevation Min M: | 36 |
| Elevation Max M: | 163 |
| Area Km2: | 11.38 |
Montigny-Lengrain (in French pronounced as /mɔ̃tiɲi lɑ̃ɡʁɛ̃/) is a commune in the Aisne department in Hauts-de-France in northern France.
On Easter day 945, the castle of Montigny-Lengrain, guarded by the faithful of King Louis IV of France, was taken by Herbert III of Vermandois, assisted by the Count of Tours and Blois Thibaud. The latter, vassal of Hugues the Great, participates in it as indirect support of Hugues to the fight against the king. (Y Sassier, Hugues Capet, Paris, Fayard, 2008, p115.)