'archmage' originates from English, specifically formed from the prefix 'arch-' (from Greek 'arkhē'/'arkhos') meaning 'chief' and 'mage' from Old French/Latin 'magus' meaning 'magician'.

'archmage' was formed in Modern English as a compound of 'arch-' + 'mage'. The element 'mage' comes via Old French from Latin 'magus', from Greek 'magos', ultimately from Old Persian 'maguš'. The prefix 'arch-' derives from Greek 'arkhē'/'arkhos' (through Latin/Old French use as a combining form), meaning 'chief' or 'principal'. The compound came into use in English literary and fantasy contexts (notably in 19th–20th century fiction and later popularized in 20th-century role-playing games).

Initially, the parts combined to mean 'chief magician' and that central sense has largely remained; over time the term became especially associated with fantasy literature, gaming, and occasionally figurative usage.