Ošljak may refer to:
- Ošljak (mountain), a mountain in Serbia
- Ošljak (island), an inhabited island in Croatia
Ošljak is an Adriatic Sea island in the Zadar Archipelago, located between the island of Ugljan and the mainland south of Zadar. Its total area is and its highest point is called Lazaret at . It has a population of 29 in the single village of Ošljak (census 2011) which is located on the western shore, overlooking Kali and Preko.