The Castelli di Cannero are three rocky islets of Lake Maggiore in northern Italy. They are located off the shoreline of Cannero Riviera while administratively forming part of the Comune of Cannobio . They are known as castelli, or castles, in recognition of the ruined ancient fortifications which are found on two of them. They are all that remains of the Rocca Vitaliana fortress built between 1519 and 1521 by Ludovico Borromeo, who gave it this name in honour of an illustrious ancestor.

The fortress was built over the ruins of an earlier castle, the Castello della Malpaga, which had been used since the 15th century as a refuge by the powerful, cruel Mazzarditi family. The five Mazzarditi brothers took control of the burgh of Cannobio between 1403 and 1404, terrorizing the inhabitants of the district with their acts of violence and piracy.