The War of the Three Sanchos () was a brief military conflict between three Spanish kingdoms in 1065–1067. The kingdoms were all ruled by kings who were first cousins: Sancho II the Strong, King of Castile; Sancho IV Garcés, King of Navarre; and Sancho Ramírez, King of Aragon, all grandsons of Sancho the Great. The primary source for the war is the thirteenth-century Primera crónica general.