Cassacco is a comune located in the Friuli-Venezia Giulia region of northeastern Italy. It falls within the regional decentralization entity of Udine, situated approximately 12 kilometres (7 mi) northwest of the city of Udine and about 80 kilometres (50 mi) northwest of Trieste.
The municipality covers a total area of 11.6 square kilometres (4.5 mi2). As of December 31, 2004, Cassacco had a recorded population of 2,880 residents.