Russia–United Kingdom relations, also Anglo-Russian relations, are the bilateral relations between the Russian Federation and the United Kingdom of Great Britain and Northern Ireland. Formal ties between the nations started in 1553. Russia and Britain became allies against Napoleon in the early-19th century. They were enemies in the Crimean War of the 1850s, and rivals in the Great Game for control of Central Asia in the latter half of the 19th century. They allied again in World Wars I and II, although the Russian Revolution of 1917 strained relations. The two countries again became enemies during the Cold War (1947–1989). Russia's business tycoons developed strong ties with London financial institutions in the 1990s after the dissolution of the USSR in 1991. Due to the Russian invasion of Ukraine, relations became very tense after the United Kingdom imposed sanctions against Russia. It was subsequently added to Russia's list of "unfriendly countries".
The two countries share a history of intense espionage activity against each other, with the Soviet Union succeeding in penetration of top echelons of the British intelligence and security establishment in the 1930s–1950s while concurrently, the British co-opted top Russian intelligence officers throughout the period including the 1990s whereby British spies such as Sergei Skripal acting within the Russian intelligence establishment passed on extensive details of their intelligence agents operating throughout Europe. Since the 19th century, England has been a popular destination for Russian political exiles, refugees, and wealthy fugitives from the Russian-speaking world.