The Château de Lagarde is a ruined castle situated near the village of Lagarde, 8 km (5.0 mi) southeast of Mirepoix in the French département of Ariège.

Following the Albigensian Crusade, the castle was handed to the Lévis-Mirepoix family. It was fortified but, over time, it was modified to provide a more comfortable residence. During the French Revolution, the castle was partially destroyed, but it remains today as a bold silhouette looking down over the valley. The ruins comprise several towers and curtain walls.

Château de Lagarde has been listed as a monument historique by the French Ministry of Culture since 1914.