Lake of Gruyère (French: Lac de la Gruyère; German: Lac de la Gruyère or Greyerzersee) is an artificial lake in the La Gruyère region of the Canton of Fribourg, Switzerland.
The reservoir was formed between the cities of Bulle and Fribourg, by building the Rossens Dam on the Sarine river in 1948. The arch dam has a height of 83 m and a crest length of 320 m. The reservoir filled in about four months after completion. The dam is operated by the Groupe E SA.
