John of Hoio (Latin: Joannes de Hoio; Croatian: Ivan de Hoio; died) was an abbot of the Cistercian Orval Abbey in present-day Belgium and Triumfontium in Luxembourg who, according to Konrad Eubel, served as the assistant bishop of Trier, simultaneously holding the title of a titular bishop of Duvno in present-day Bosnia and Herzegovina. Dominik Mandić, while researching the history of the Diocese of Duvno, could not find any documents on him, thus being unable to determine whether John of Hoio ever served as the residential bishop in Duvno. At the end of his life, John returned to the Orval Abbey, where he is buried.