Volga (Anc. Rha), a river of Russia, the longest in Europe. It rises on the plateau of Valdai, in the western part of the government of Tver, near the head waters of the Diina, in lat. 57° N., Ion. 33° E., flows a circuitous easterly, and then a southerly and southeasterly course, passing by the towns of Tver, Yaroslav, Kostroma, Nizhni Novgorod, Kazan, Simbirsk, Samara, Saratov, and Astrakhan, capitals of the governments of the same names, and near the last named town falls into the Caspian sea by a great number of mouths. Its length is about 2,300 m., and its total fall is little more than 600 ft. Its basin is estimated at upward of 500,000 sq. m. Its principal affluents from the right are the Oka and the Sura, and from the left the Tvertza, Mologa, Kostroma, Unsha, Vetluga, Kama, Samara, and Irgis. Numerous canals connect it with the Baltic and White seas, making it the great artery of communication for European Russia, though its navigation is frequently interrupted by sand banks and changes of channel, and obstructed by ice during half of the year.

It abounds in fish, including salmon and sturgeon, which are largely exported.