The municipality of Sori contains the frazioni (subdivisions, mainly villages and hamlets) Canepa, Capreno, Lago, Levà, Polanesi, San Bartolomeo di Busonengo, Sant’Apollinare, Sussisa, and Teriasca.
According to some theories, Sori was founded by Greek immigrants around the 7th century BC. Most likely, the small port was also used by the Romans, although the first mention of the town dates to the early Middle Ages, when it was a possession of the bishops of Milan; later, it was part of the Republic of Genoa.