- a sovereign prince of the former ruling house of Austria
- The title of Archduke (feminine: Archduchess) (German: Erzherzog, feminine form: Erzherzogin) denotes a noble rank above Duke and below King, used primarily by princes of the Houses of Habsburg and Habsburg-Lorraine.
- The Archdukes are a genus (Lexias) of tropical forest-dwelling butterflies that are common throughout Southeast Asia and Australasia. Members of the brush-footed butterfly family Nymphalidae, the genus is represented by about 17 species. ...
- Title for the dukes of Austria, Lorraine, and Brabant, There is an informal SCA meaning for this term usually construed to mean a ‘duke’ who was reigned more than five times.