The Kiev Reservoir (Ukrainian: Київське водосховище, Kyyivs’ke vodoskhovyshche), locally the Kiev Sea, is a large water reservoir located on the Dnieper River in Ukraine. Named after the city of Kiev, which lies to the south, it covers a total area of 922 square kilometres within the Kiev Oblast. The reservoir was formed in 1960-1966, as a result of the Kiev Hydroelectric Power Plant dam being built at Vyshhorod. The reservoir is mainly used for hydroelectricity generation, industrial and public consumption, and irrigation.

The reservoir is 110 km in length, 12 km in width, has a depth of four to eight meters, a volume of 3.7 km³, and a usable volume of 1.2 km³. The reservoir, together with the Kakhovka Reservoir, the Dnieper Reservoir, the Dniprodzerzhynsk Reservoir, the Kremenchuk Reservoir, and the Kaniv Reservoir, has created a deep-water route on the river. However, the construction has also contributed to significant environmental problems such as the diminished flow velocity which reduces water oxygenation, and has a negative result on the balance of aquatic life forms. Also, during its construction some nearby villages were flooded. One of these was Teremtsi, where the residents of the village persuaded Soviet authorities to let them stay, only to be evacuated later in 1986.

Kiev or Kyiv (Ukrainian: Київ [ˈkɪjiw] ( listen); Russian: Киев) is the capital and the largest city of Ukraine, located in the north central part of the country on the Dnieper River. The population as of the 2001 census was 2,611,300. However, higher numbers have been cited in the press.

Kiev is an important industrial, scientific, educational and cultural centre of Eastern Europe. It is home to many high-tech industries, higher education institutions and world-famous historical landmarks. The city has an extensive infrastructure and highly developed system of public transport, including the Kiev Metro.

The name Kiev is said to derive from the name of Kyi, one of four legendary founders of the city (brothers Kyi, Shchek, Khoryv, and sister Lybid). During its history, Kiev, one of the oldest cities in Eastern Europe, passed through several stages of great prominence and relative obscurity. The city probably existed as a commercial centre as early as the 5th century. A Slavic settlement on the great trade route between Scandinavia and Constantinople, Kiev was a tributary of the Khazars, until seized by the Varangians (Vikings) in the mid-9th century. Under Varangians rule, the city became a capital of the Rus', the first East Slavic state. Completely destroyed during the Mongol invasion in 1240, the city lost most of its influence for the centuries to come. It was a provincial capital of marginal importance in the outskirts of the territories controlled by its powerful neighbours; first the Grand Duchy of Lithuania, followed by Poland and Russia.