| Lamonzie-Montastruc | |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason ville fr Lamonzie-Montastruc 24.svg |
| Arrondissement: | Bergerac |
| Canton: | Bergerac-2 |
| Insee: | 24224 |
| Postal Code: | 24520 |
| Mayor: | Jean-Michel Dreuil[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | CA Bergeracoise |
| Coordinates: | 44.8964°N 0.5944°W |
| Elevation M: | 65 |
| Elevation Min M: | 48 |
| Elevation Max M: | 162 |
| Area Km2: | 20.66 |
Lamonzie-Montastruc (in French pronounced as /lamɔ̃zi mɔ̃tastʁyk/; Occitan (post 1500);: La Móngia de Montastruc) is a commune in the Dordogne department in Nouvelle-Aquitaine in southwestern France. It boasts two primary chateaux. One is Le Château de Montastruc, an antique troglodytic site, then a fortress, arranged progressively through its 1500 years of history. Le Château de Montastruc is listed as a French Historical Monument. The other is Le Château de Bellegarde, originating from the 14th Century, although the interiors are of the 20th century.