| Conflict: | Battle of Comacchio |
| Date: | 809 |
| Place: | Comacchio, Italy |
| Result: | Frankish victory |
| Combatant1: | Carolingian Empire |
| Combatant2: | Byzantine Empire |
| Commander1: | Unknown |
| Commander2: | Paul |
The Battle of Comacchio in 809 was a naval battle between a Byzantine fleet dispatched from Venice and the Frankish garrison of the island of Comacchio. A Byzantine fleet from Constantinople under its commander Paul, the governor of Cephalonia, arrived in Venice by way of Dalmatia and sent a fleet detachment to anchor at Comacchio. They skirmished with the Franks, were defeated and retreated to Venice.