The lake is situated Verkhnedvinsk District, Vitebsk Region (the basin of the river Drysa). It belongs to the territory of Osveyski Landscape Reserve.
The Degtyaryovka River connects Osveyskoye with Lake Lisno.
Osveyskoye is the second largest lake in Belarus. Area Ч 52.8 square km, maximum depth Ч 7.5 metres, average depth Ч 2 metres, length Ч 11.4 metres, width Ч 7.8 metres, coastline Ч 33.4 km, mineral water content Ч 200-250 milligrams per litre, transparency Ч 2.3 metres. The lake is located 129.8 metres above the sea level. Catchment basin Ч 259 square km.
There is an island in the western part of the lake (5 square km).
Lake Osveyskoye is rich in fish (pike, bream, pike perch, carp, burbot, etc.) The coastline is inhabited by beavers and muskrats, as well as numerous representatives of the fowl world, including the mute swan and the small gull.
The local archeological attractions include ruins of ancient settlements and burial places by the villages of Chapayevskaya, Uragovo and Sukali.
Lake Osveyskoye is an ecosystem of international importance. Belarusian scientists are working on projects aimed at preservation of its unique environment and ichthyofauna.