Lake Yliki (Greek: Υλίκη Yliki, Ancient Greek: Ὑλίκη Hylike, Latinised as Hylica[1]) is a large natural lake of Boeotia, central Greece.

Situated 8 km north of Thebes at 78 m elevation, it has been an important source of drinking water for the Athens agglomeration since 1958.

[2] It is surrounded by low mountains, which separate it from the drained Lake Copais.

The lake is home to several threatened endemic or near-endemic fish species:[3] (IUCN Red List status shown) Some scenes of French-singer Indila's music video "S.O.S" were filmed at the lake.

[4] Media related to Lake Yliki at Wikimedia Commons