The Château de Frankenbourg is a ruined 12th century castle in the commune of Neubois in the Bas-Rhin département in Alsace, France.
The castle is state-owned. It has been listed since 1898 as a monument historique by the French Ministry of Culture.
Coordinates: 48°17′43″N 7°19′30″E / 48.29528°N 7.32500°E