The Sura (Russian: Сура́, Chuvash: Сăр, Săr) is a river in Russia, a north-flowing right tributary of the Volga. Its mouth on the Volga is about halfway between Nizhny Novgorod and Kazan. It flows through Penza Oblast, Mordovia, Ulyanovsk Oblast, Chuvashia and Nizhny Novgorod Oblast. It is 841 kilometres long, and has a drainage basin of 67,500 square kilometres. It is navigable for 394 km from the mouth.
