His father was Imperial Prince Abo who was the eldest son of Emperor Heijo and his mother, Imperial Princess Ito, was a daughter of Emperor Kanmu, meaning Narihira was a grandson of Emperor Heijo and a great grandson of Emperor Kanmu in terms of his paternal lineage and a grandson of Emperor Kanmu in terms of his maternal lineage.
父は平城天皇第一皇子の阿保親王、母伊都内親王は桓武天皇の皇女で、業平は父方をたどれば平城天皇の孫・桓武天皇の曾孫であり、母方をたどれば桓武天皇の孫にあたる。