Mesøya is an island in Meløy in Nordland. The island is located southwest of Ørnes. Mesøya has an area of 8 km², and the highest point on the island is Mesøytoppen at 364 metres above sea level.
Coordinates: 66°51′N 13°39′E / 66.85°N 13.65°E / 66.85; 13.65