Fontus Lake (Bulgarian: езеро Фонт, romanized: ezero Font, IPA: [ˈɛzɛro ˈfɔnt]) is the oval-shaped 150 m long in south-southwest to north-northeast direction and 100 m wide lake in the middle part of South Beaches on Byers Peninsula, Livingston Island in the South Shetland Islands, Antarctica.

It has a surface area of 1.9 ha and is separated from sea by a 53 to 64 m wide strip of land.

[2] The feature is named after Fontus, a Roman deity of springs and streams, son of Juturna.

[1] Fontus Lake is centred at 62°39′40.4″S 61°00′19″W / 62.661222°S 61.00528°W / -62.661222; -61.00528, which is 600 m northeast of Dometa Point and 740 m south of Negro Hill.

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