Athina Hélène Onassis (Greek: Αθηνά Ωνάση; born Athina Hélène Roussel (Greek: Αθηνά Ρουσσέλ), 29 January 1985) is a French-Greek heiress and equestrian, the only surviving descendant of Greek shipping magnate Aristotle Onassis, and the only child of Aristotle's daughter Christina Onassis.

She makes rare public appearances.