Viktor Vasylovych Postol (Ukrainian: Віктор Васильович Постол; born 16 January 1984) is a Ukrainian professional boxer who held the WBC light-welterweight title from 2015 to 2016 and challenged twice for the WBO light-welterweight title in 2016 and in 2020. As of May 2021, he is ranked as the world's fifth best active light-welterweight by the Transnational Boxing Rankings Board and by BoxRec and fourth by The Ring magazine.