'''Demyanyuk''', '''Dem'yanyuk''' or '''Demjanjuk''' ({{langx|uk|Дем'янюк}}) is a patronymic surname of Ukrainian origin, meaning "child of Demyan". Notable people with the surname include:
*Dmytro Dem'yanyuk (born 1983), Ukrainian high jumper *John Demjanjuk (1920–2012), Ukrainian-American Nazi concentration camp guard *Oleksiy Demyanyuk (1958–1999), Soviet high jumper
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Category:Patronymic surnames Category:Surnames of Ukrainian origin Category:Ukrainian-language surnames