| En Name: | Lesnoy |
| Ru Name: | Лесной |
| Coordinates: | 58.6333°N 106°W |
| Map Label Position: | right |
| Image Coa: | Coat of Arms of Lesnoy (Sverdlovsk oblast).png |
| Federal Subject: | Sverdlovsk Oblast |
| Adm City Jur: | closed administrative-territorial formation of Lesnoy |
| Adm Ctr Of1: | closed administrative-territorial formation of Lesnoy |
| Inhabloc Cat: | Town |
| Urban Okrug Jur: | Lesnoy Urban Okrug |
| Mun Admctr Of: | Lesnoy Urban Okrug |
| Leader Title: | Mayor |
| Leader Name: | Sergey Cherepanov |
| Pop 2010Census: | 50363 |
| Pop 2010Census Rank: | 316th |
| Established Date: | 1947 |
| Postal Codes: | 624200 |
| Dialing Codes: | 34342 |
Lesnoy (Russian: Лесно́й) is a closed town in Sverdlovsk Oblast, Russia, located 254km (158miles) north of Yekaterinburg on the banks of the Tura River. Population:
It was founded in 1947 when Plant 418 was constructed to produce highly enriched uranium (HEU) for the production of nuclear weapons. Nuclear weapons were also assembled there. In 1954, it became the closed town of Sverdlovsk-45 to support production of nuclear weapons.[1]
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—an administrative unit with the status equal to that of the districts.[2] As a municipal division, the closed administrative-territorial formation of Lesnoy is incorporated as Lesnoy Urban Okrug.[3]