| Sedanka | |
| Map: | Alaska |
| Native Name: | Sidaanax̂ |
| Native Name Link: | Aleut language |
| Location: | Northern Pacific Ocean |
| Coordinates: | 53.7833°N -166.1914°W |
| Archipelago: | Aleutian Islands |
| Area Sqmi: | 39.889 |
| Length Km: | 16.6 |
| Elevation Ft: | 1,345 |
| Country: | United States |
| Country Admin Divisions Title: | State |
| Country Admin Divisions: | Alaska |
| Country Admin Divisions Title 1: | Borough |
| Country Admin Divisions 1: | Aleutians East |
| Population: | Uninhabited |
Sedanka Island (ale|Sidaanax̂[1]) is an island in the Fox Islands group of the eastern Aleutian Islands, Alaska. It is 10.3miles long and is situated off the northeast coast of Unalaska Island. It has a land area of 39.889sqmi and no permanent population.