Dorothee Island (French: Ile Dorothee) is an island in the Australian state of South Australia which is part of the Pearson Isles which itself is part of the larger island grouping known as the Investigator Group. It is located about 69 kilometres (43 miles) west south-west of Cape Finniss on the west coast of Eyre Peninsula. It was discovered as part of the Pearson Isles by Matthew Flinders on 13 February 1802. The island was given its name in August 1969 in order to preserve a name used within the locality by the Baudin expedition. The island has enjoyed protected area status since at least 1972 and since 2011, it been part of the Investigator Group Wilderness Protection Area.