R21 highway (Russia)

Federal Highway R21 shield}}
Federal Highway R21
Федеральная автомобильная дорога Р21
Kola Highway
Route information
Part of E105
Length1,592 km (989 mi)
Existed1986–present
HistoryWas M18 from 1986–2018
Major junctions
North endNorwegian border near Borisoglebsky
South endMoskovsky Prospekt in St. Petersburg
Location
CountryRussia
Highway system

The R21 highway (in Cyrillic Р21), also known as the Kola Motorway, is a major highway in Russia, running from Saint Petersburg to Murmansk. The highway is part of European route E105 and is the main transportation route by road in the Republic of Karelia and the Murmansk Oblast. Its length is 1592 kilometers. Before 2018, the R21 was designated as M18.