Dionysius (disambiguation)

Dionysius is a Romanized form of the Greek name Dionysios.

Dionysius may also refer to:
 * Dionysius the Areopagite, early Christian convert and saint
 * Pseudo-Dionysius the Areopagite, a pseudepigraphical Christian theologian and mystic
 * Dionysius of Halicarnassus
 * Dionysius Exiguus, inventor of the Anno Domini dating system
 * Dionysius (album), a 1983 album by jazz drummer Dannie Richmond
 * Dionysiou Monastery, an Eastern Orthodox monastery at the monastic state of Mount Athos in Greece
 * Dionysia (plant), a plant genus
 * Dionysia, a large festival in ancient Athens in honor of the god Dionysus
 * Agios Dionyssios, Patras, a neighbourhood in the city of Patras, Greece
 * Dionysius (crater), a lunar impact crater
 * Dionysius (journal), a classics publication of Dalhousie University
 * St Dionysius' Church, Market Harborough, a church of the Church of England, Leicestershire
 * St. Dionysius Institute in Paris, an Orthodox Christian theological institute in Paris, France
 * Dionysiou Areopagitou Street, a street in Athens
 * Codex Athous Dionysiou, a manuscript of the New Testament
 * Dionysius, a Greek orator and teacher of Marcus Cornelius Fronto
 * Saint Dionysius (disambiguation)
 * Dionysius Patrick O'Brien (born 1934), English musician