Kassari
| Beach of Kassari | |
| Geography | |
|---|---|
| Coordinates | 58°48′00″N 22°50′00″E / 58.80000°N 22.83333°E | 
| Area | 19.3 km2 (7.5 sq mi) | 
| Administration | |
| County | Hiiu County | 
Kassari is an Estonian island. It has an area of 19.3 km2 with a population of around 300. It has a museum dedicated to Oskar Kallas and Aino Kallas.
The philosopher and pedagogue Ülo Kaevats (1947–2015) was born on Kassari.
- The tongue of land in Kassari