The Siege of Trsat () was a battle fought over possession of the town of Trsat () in Liburnia, near the Croatian–Frankish border. The battle was fought in the autumn of 799 between the defending forces of the Dalmatian Croatia under the leadership of Croatian duke Višeslav and the invading Frankish army of the Carolingian Empire led by Eric of Friuli. The battle was a Croatian victory, and the Frankish commander Eric was killed during the siege.