| Citadel Island | |
| Map: | Australia Victoria South Gippsland Shire |
| Location: | Bass Strait |
| Coordinates: | -39.1149°N 146.2379°W |
| Area Ha: | 18 |
| Length M: | 675 |
| Width M: | 415 |
| Elevation M: | 110 |
| Country: | Australia |
| Country Admin Divisions Title: | State |
| Country Admin Divisions: | Victoria |
Citadel Island is a small, rugged, granite island in the Glennie group of islands off the west coast of Wilsons Promontory, Victoria, Australia.[1] It is the site of the first automatic acetylene powered lighthouse installed by Australia's Commonwealth Lighthouse Service.[2] There is no public access. The island is part of the Wilsons Promontory Islands Important Bird Area, identified as such by BirdLife International because of its importance for breeding seabirds.[3]