Proteus Lake (Bulgarian: езеро Протей, romanized: ezero Protey, IPA: [ˈɛzɛro proˈtɛj]) is the roughly pentagonal lake extending 300 m in west–east direction and 220 m in south–north direction in the central part of Flamingo Beach on the north coast of Greenwich Island in the South Shetland Islands, Antarctica.

It has a surface area of 3.9 ha and is separated from the waters of Orión Passage by a 20 to 35 m wide strip of land.

[2] The feature is named after the water deity Proteus in Greek mythology.

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

This Greenwich Island location article is a stub.