Osip Emilyevich Mandelstam (Russian: О́сип Эми́льевич Мандельшта́м, IPA: [ˈosʲɪp ɪˈmʲilʲjɪvʲɪtɕ məndʲɪlʲˈʂtam]; 14 January [O.S. 2 January] 1891 – 27 December 1938) was a Russian and Soviet poet. He was the husband of Nadezhda Mandelstam and one of the foremost members of the Acmeist school of poets. He was arrested by Joseph Stalin's government during the repression of the 1930s and sent into internal exile with his wife.

Given a reprieve of sorts, they moved to Voronezh in southwestern Russia. In 1938 Mandelstam was arrested again and sentenced to five years in a corrective-labour camp in the Soviet Far East. He died that year at a transit camp near Vladivostok.