Agnes of Aquitaine (end of 1072 – 6 June 1097) was a daughter of William VIII, Duke of Aquitaine and his third wife Hildegarde of Burgundy, and thus half-sister of Agnes of Aquitaine, Queen of Castile, with whom she is sometimes confused.
In 1081, Agnes was betrothed to Peter I of Aragon and Navarre. During 1086 in Jaca the couple married, and upon Peter's succession, Agnes became queen consort of Aragon and Navarre. By him, Agnes had two children, both of whom predeceased their father:
Agnes died in 1097, and her husband remarried to a woman named Bertha.