The Lake of Sainte-Croix (French: Lac de Sainte-Croix, pronounced [lak də sɛ̃tkʁwa]) is a reservoir in Southern France that was formed by the construction, between 1971 and 1974 (when it was put into service),[1] of a reinforced-concrete arch dam, the Sainte-Croix Dam [fr].

It marks the departmental border between Var to the southeast and Alpes-de-Haute-Provence to the northwest.

It holds a maximum of 761 million cubic metres of water.

The village of Les Salles-sur-Verdon stands by the lake; it was rebuilt on the shore after the original lower village was destroyed to make room for the reservoir.

The lake comprises a sole island, the Île de Costebelle (Island of Costebelle), part of the commune of Les Salles-sur-Verdon.