Abellio (also Abelio and Abelionni) was a god worshipped in the Garonne Valley in Gallia Aquitania (now southwest France), known primarily by a number of inscriptions which were discovered at Comminges. He may have been a god of apple trees.

Some scholars have postulated that Abellio is the same name as Apollo, who in Crete and elsewhere was called Abelios (Greek Αβέλιος), and by the Italians and some Dorians Apello, and that the deity is the same as the Gallic Apollo mentioned by Caesar, and also the same as the Belis or Belenus mentioned by Tertullian and Herodian.

Other scholars have taken the reverse position that Abellio might have been a similar solar deity of Celtic origin in Crete and the Pyrenees, but the Cretan Abellio may however not be the same god as the Celtic one, but rather a different manifestation, or dialectal form, of the Greek god Apollo or his name.

 This article incorporates text from a publication now in the public domain: Smith, William, ed. (1867). "^{article name needed}". Dictionary of Greek and Roman Biography and Mythology.