Arcadius may refer to:
- Flavius Arcadius (377-408), Byzantine emperor
- Arcadius of Antioch, Greek grammarian
- Arkadios II, Monothelite archbishop of Cyprus
- Arcadius of Mauretania, 4th-century martyr
- Arcadius of Bourges, bishop and saint
- Arcadius (d. 437), martyr