'Appalachia' ultimately derives from the name of the 'Apalachee', a Native American people encountered by Spanish explorers; the Spanish form 'Apalache'/'Apalachee' was applied to regions and later to the mountains.

'Appalachia' came into English via Spanish ('Apalachee') and French references to the people and places; the name was extended to the 'Appalachian' Mountains and later to the wider region, producing the modern form 'Appalachia'.

Originally it referred to the 'Apalachee' people; over time the name was transferred to the nearby mountains and then broadened to mean the larger cultural and geographic region now called 'Appalachia'.