The oldest evidence of the name is an entry in the Papal Chancery dated 10 August 1314 which states that "William de Caldore granted this castle with all its appurtenances to the monastery of Cawdor". This confirms that the family had been lords of Cawdor for more than 100 years by this time. The spelling on the original document was probably "Caldor", but this has been altered over time to create the current form of the name.