Dionysius \di(o)-ny-sius\ as a boy's name. Greek mythology: Dionysius was the Greek god of wine (known to Romans as Bacchus). Also the name of a man converted by Saint Paul, and traditionally considered the first bishop of Athens. Dennis is an offshoot of this name.

Dionysius has 7 variant forms: Dion, Dionio, Dionisio, Dioniso, Dionysios, Dionysos and Dionysus.

For more information, see also related names Deion, Denis and Dwight.

A baby name that sounds like Dionysius is Thanasis.