RusHydro (previous name: Hydro-OGK, Russian: РусГидро; traded as: MICEX-RTS: HYDR) is a Russian hydroelectricity company. As of early 2012 it has a capacity of 34.9 gigawatts. It is the world's second-largest hydroelectric power producer and is the country's largest power-generating company and the largest successor to RAO UES. The conglomerate, which is partly government-owned, underwent a major consolidation beginning in July, 2007. The head of the company is Yevgeny Dod. Its head office is in Obruchevsky District, South-Western Administrative Okrug, Moscow.

On 17 August 2009, an accident accured at RusHydro's largest plant at Sayano-Shushenskaya in eastern Siberia. The turbine hall and engine room were flooded, the ceiling of the turbine hall collapsed, 9 of 10 turbines were damaged or destroyed, and 75 people were killed. The entire plant output, totaling 6,400 MW and a significant portion of the supply to the local grid, was lost, leading to widespread power failure in the local area, and forcing all major users such as aluminum smelters to switch to diesel generators. The plant was restarted at reduced output power on 24 February 2010.