Sea Lion Tarn (Bulgarian: езеро Морски Лъв, romanized: ezero Morski Lav, IPA: [ˈɛzɛro ˈmɔrski ˈɫɤf]) is a freshwater tarn with an area of 0.3 ha (0.74 acres) located between Sea Lion Glacier and the north-western slopes of Atlantic Club Ridge on Hurd Peninsula in eastern Livingston Island in the South Shetland Islands, Antarctica.

The lake drains westward through a 100 m creek into South Bay.

The feature takes its name from the adjacent Sea Lion Glacier.

The midpoint is located at 62°38′48″S 60°22′14″W / 62.64667°S 60.37056°W / -62.64667; -60.37056 (Bulgarian mapping from a 1995-1996 ground survey).

This article includes information from the Antarctic Place-names Commission of Bulgaria which is used with permission.