The lake Sultartangarlón (Icelandic pronunciation: [ˈsʏl̥tarˌtʰauŋkarˌlouːn] ) is situated in the Highlands of Iceland to the north of the volcano Hekla. It is a reservoir of the river Þjórsá. Its surface area is 20 km.

Many reservoirs have been constructed and are being constructed in the highlands, which raises questions in Icelandic society about the roles and interests of industry and environment.

• List of lakes of Iceland
• Geography of Iceland