France
- Castres (Aisne), commune located in the Aisne department of the region of Picardy
- Castres (Tarn), commune located in the Tarn department in the region of Midi-Pyrenees
- Castres-Gironde, commune located in the Gironde department in theAquitaine
- Arrondissement of Castres, administrative subdivision, located in the department of Tarn and in the region of Occitania