Peire de Castelnou (also Castelnau or Chasselnou, ) was a minor troubadour from Provence. He was a client of the lords of Baux. His one surviving piece, "Oimais no·m cal far plus long'atendensa", is a "sirventes" ("soldier's song") written after either the Battle of Benevento (1266) or the Battle of Tagliacozzo (1268). He favoured the Angevin cause in Italy.