Øyungen is a lake in the municipality of Holtålen in Trøndelag county, Norway. The 6.13-square-kilometre (2.37 sq mi) lake lies about 7 kilometres (4.3 mi) southwest of the village of Hessdalen. The Forollhogna National Park surrounds the lake on three sides.

The first part of the name is øy which means "island". The last element -ungen (Old Norse: -ungr) is a common suffix in names of lakes in Norway, for instance Kaldungen (meaning "the lake with cold water"), Svartungen (meaning "the black lake", Leirungen (meaning "the lake with clay"), and Sandungen (meaning "the lake with sand"). The lake Øyungen contains several small islets.

• List of lakes in Norway