Sergei Chavain, also spelled Čavajn (Mari: Сергей Чавайн, pronounced [tʃɑˈβɑɪn]; 6 October 1888, Maly Karamas – 11 November 1937) was a Mari poet and playwright, born Sergei Grigorievich Grigoriev (Russian: Серге́й Григо́рьевич Григо́рьев).In 1905 he wrote the first literary poem in the Mari language, Oto (Ото – The Grove). In 1908 he graduated from Kazan Teachers' Seminary. His first play was The Wild Duck in 1912, a satire of Tsarist bureaucrats.