Dionysius III

Dionysius III can refer to:
 * Dionysius III of Antioch, Syriac Orthodox Patriarch of Antioch in 958–961
 * Dionysius III of Constantinople, Metropolitan of Larissa in 1652–1662, Ecumenical Patriarch of Constantinople in 1662–1665
 * Mar Dionysius III, Malankara Metropolitan in 1817–1825