Lesnoy (Russian: Лесно́й) is a closed town in Sverdlovsk Oblast, Russia, located 254 kilometers (158 mi) north of Yekaterinburg on the banks of the Tura River.

[6] It was founded in 1947 when Plant 418 was constructed to produce highly enriched uranium (HEU) for the production of nuclear weapons.

In 1954, it became the closed town of Sverdlovsk-45 to support production of nuclear weapons.

[7] Sverdlovsk-45 remained secret until President Boris Yeltsin decreed in 1992 that such places could use their historical names; the town had not appeared on official maps until then.

Within the framework of the administrative divisions, it is, together with one work settlement and three rural localities, incorporated as the closed administrative-territorial formation of Lesnoy[1]—an administrative unit with the status equal to that of the districts.