| Mortefontaine | |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason mortefontaine 60.svg |
| Arrondissement: | Senlis |
| Canton: | Senlis |
| Intercommunality: | CC de l'Aire Cantilienne |
| Demonym: | Mortifontain |
| Insee: | 60432 |
| Postal Code: | 60128 |
| Mayor: | Jacques Fabre[1] |
| Term: | 2020 - 2026 |
| Coordinates: | 49.1131°N 2.6003°W |
| Elevation M: | 93 |
| Elevation Min M: | 60 |
| Elevation Max M: | 203 |
| Area Km2: | 15.29 |
Mortefontaine (pronounced as /fr/) is a commune in the Oise department in Northern France.
The 17th-century Château de Mortefontaine was bought by Joseph Bonaparte,[2] elder brother of Napoléon Bonaparte, in 1798. The Convention of 1800 (also known as the Treaty of Mortefontaine), a friendship treaty between France and the United States, was signed in the castle. The preliminaries of the 1802 Peace of Amiens were also negotiated there.