Sunday Island is a low-lying, sandy, 16.2 km² barrier island on the coast of Victoria, Australia. It is about 8 km long by 3 km wide and rises to a maximum height of no more than 15 m asl. It lies in Corner Inlet, South Gippsland, 4 km south-west of Port Albert and 215 km south-east of Melbourne. Although the island is surrounded by the Nooramunga Marine and Coastal Park, it is private freehold property, a game reserve owned by the Para Park Cooperative.