The Assos Castle (Greek: Κάστρο της Άσσου, romanized: Kastro tis Assou) is a Venetian fortification on Cephalonia island in western Greece.

It overlooks the bay of Agia Kyriaki, north of Paliki, and could act as a base from which to defend the island, to protect against pirates as well as a naval invasion.

[1] The castle stands on the top of a 170m high rocky hill, which encompasses the entire peninsula of Assos.

[3] At the time Venice had a plan for protecting territories in the east by founding a city within the castle and moving their administration there from St. George's.

Gentillini eventually married and settled in Cephalonia, and his name was inscribed in the Libro d'Oro of noble families.

Parts of the walls and an arched entrance gate with the Venetian Lion of Saint Mark[6] are the mainly preserved sections.