Mortagne may refer to:
- Mortagne (river), a river in northeastern France
- places in France:
- Mortagne, Vosges, in the Vosges department
- Mortagne-au-Perche, in the Orne department
- Mortagne-du-Nord, in the Nord department
- Mortagne-sur-Gironde, in the Charente-Maritime department
- Mortagne-sur-Sèvre, in the Vendée department
- Bec-de-Mortagne, in the Seine-Maritime department