Tsiolkovsky is a closed town in Amur Oblast, Russia, located on the Bolshaya Pyora River, 110 kilometers (68 mi) from the border with China and 180 kilometers (110 mi) north of Blagoveshchensk, the administrative center of the oblast. Population: 5,892 (2010 Russian census); 5,050 (2002 Census). The town serves the nearby spaceport, Vostochny Cosmodrome.

A closed city or town is a settlement where travel or residency restrictions are applied so that specific authorization is required to visit or remain overnight. Such places may be sensitive military establishments or secret research installations that require much more space or internal freedom than is available in a conventional military base. There may also be a wider variety of permanent residents, including close family members of workers or trusted traders who are not directly connected with clandestine purposes.