Long Island is an island in Fiordland, in the southwest of New Zealand's South Island. It lies within Dusky Sound, to the southeast of Resolution Island, and is separated from it and the South island mainland by Bowen Channel to the north, and from the South Island mainland by Cook Channel to the south.
Long Island is 12 kilometres (7.5 mi) in length and a maximum of 2 kilometres (1.2 mi) in width.
Coordinates: 45°45′47″S 166°41′49″E / 45.7630°S 166.6970°E