Grigori Yefimovich Rasputin (; Russian: Григорий Ефимович Распутин [ɡrʲɪˈɡorʲɪj jɪˈfʲiməvʲɪtɕ rɐˈsputʲɪn]; 21 January [O.S. 9 January] 1869 – 30 December [O.S. 17 December] 1916) was a Russian mystic and self-proclaimed holy man. He is best-known for having befriended the royal family of Nicholas II, the last Emperor of Russia, through whom he gained considerable influence in the later years of the Russian Empire.

Rasputin was born to a family of peasants in the Siberian village of Pokrovskoye, located within Tyumensky Uyezd in Tobolsk Governorate (present-day Yarkovsky District in Tyumen Oblast). He had a religious conversion experience after embarking on a pilgrimage to a monastery in 1897, and has been described as a monk or as a strannik (wanderer or pilgrim), though he held no official position in the Russian Orthodox Church. In 1903 or in the winter of 1904–1905, he travelled to Saint Petersburg and captivated a number of religious and social leaders, eventually becoming a prominent figure in Russian society. In November 1905, Rasputin met Nicholas II and his empress consort, Alexandra Feodorovna.

In late 1906, he began acting as a faith healer for Nicholas' and Alexandra's only son, Alexei Nikolaevich, who was suffering from haemophilia. He was a divisive figure at court, seen by some Russians as a mystic, visionary, and prophet, and by others as a religious charlatan. The extent of Rasputin's power reached an all-time high in 1915, when Nicholas left Saint Petersburg to oversee the Imperial Russian Army as it was engaged in World War I. In Nicholas' absence, Rasputin and Alexandra consolidated their influence across the Russian Empire. However, as Russian military defeats mounted on the Eastern Front, both figures became increasingly unpopular, and in the early morning of 30 December [O.S. 17 December] 1916, Rasputin was assassinated by a group of conservative Russian noblemen who opposed his influence over Alexandra and Nicholas.

Historians often suggest that Rasputin's scandalous and sinister reputation helped discredit the Tsarist government, thus precipitating the overthrow of the House of Romanov shortly after his assassination. Accounts of his life and influence were often based on hearsay and rumor; he remains a mysterious and captivating figure in popular culture.