Oskol Reservoir
The village of Yatskivka on the reservoir in 2019
Oskol Reservoir
Location	Kharkiv Oblast
Coordinates	49°17′34″N 37°34′16″E / 49.29278°N 37.57111°E / 49.29278; 37.57111
Type	reservoir
Primary inflows	Oskil River
Primary outflows	Oskil River
Basin countries	Ukraine
Max. length	125 km (78 mi) (before destruction)
Max. width	4 km (2.5 mi) (before destruction)
Surface area	130 km2 (50 sq mi) (before destruction)
Average depth	4 m (13 ft) (before destruction)
Water volume	474 hm3 (384,000 acre⋅ft) (before destruction)

The Oskil Reservoir (Ukrainian: Оскільське водосховище; Russian: Оскольское водохранилище, sometimes translated as Oskol, Oskilske -) was an artificial lake on the Oskil River in Kharkiv Oblast, Ukraine. It was formerly known as the Chervony-Oskil Reservoir.

The reservoir was opened in 1958. Before it was drained, the reservoir's area was 130 km², with a maximal length of 125 km, a maximal width of 4 km, an average depth of 4 m and a volume of approximately 474 hm³. The purpose of the reservoir was to regulate water levels, to serve as a source for electricity, and to help the fishing industry.^[1]

During the 2022 Russian invasion of Ukraine, the reservoir was noted for its strategic importance, as causing downstream flooding would be one way to slow Russian advances in the Donbas.^[2]

In July 2022, Russian shelling destroyed the reservoir's Oskil Dam, draining its level to one-sixth that of its pre-war size.^[3] The loss of water from the reservoir caused significant environmental damage, including the deaths of millions of fish and other endangered species.^{[1] [3]}