Olha Yuriivna Hasyn (Ukrainian: Ольга Юріївна Гасин, nee Pelenychka, 19 September 1913, Koniukhiv, Austria-Hungary – 27 July 1979, Brovary, Soviet Union) – undercover agent of Organization of Ukrainian Nationalists, assistant and liaison officer of Roman Shukhevych, the leader of the Ukrainian Insurgent Army, and of Oleksa Hasyn, her husband and an important figure in UIA. In her native village there is a museum dedicated to her. Also, a street in Brovary is named after her.