'Elsass' originates from German, specifically the Old High German word 'Elsâzi' or 'Elsâz', where the second element is related to Old High German 'saz' meaning 'seat' or 'settlement'.

'Elsass' changed into the Medieval Latin/French form 'Alsatia' / 'Alsace' and the German form 'Elsass' persisted in German usage; the modern English and French 'Alsace' reflect the Latin/French evolution while German retains 'Elsass'.

Initially it denoted a specific territory or 'seat/settlement' on the western edge of the Rhine; over time it came to denote the wider historical and cultural region now known as Alsace.