Lifespan: Tenshō 4 (1576) to Kanei 14 (1637)
Other Names: Manzō, Sakujirō
Title: Governor of Iwami, General of the Right Division, Governor of Buzen
Clan: Ryūzōji, Isahaya-Nabeshima
Father: Ryūzōji Ieharu
Siblings: Kiyonao, Naonori
Wife: Shōkain (daughter of Ryūzōji Masaie), Hikokiku (third daughter of Nabeshima Naoshige)
Children: Daughter (formal wife of Nabeshima Shigekazu), Hikomiya, Shigeyoshi
Isahaya Naonori served as a bushi from the Azuchi-Momoyama to early Edo periods. He was the second head of the Isahaya-Nabeshima family.
In 1576, Naonori was born as the second son of Ryūzōji Ieharu, the first head of the Isahaya-Nabeshima family which was one of the Four Families of the Ryūzōji – four families from the Ryūzōji clan folded into the governance structure of the Saga domain by the Nabeshima clan in the Edo period. Kiyonao was the grandson of Ryūzōji Akikane.
His older brother, Isahaya Kiyonao, did not get along well with their father so Naonori inherited the headship of the clan.
In the era of Naonori, the family surname was changed from Ryūzōji to Isahaya. The name is derived from a placename where he resided. It is pronounced the same but written with different characters.
Naonori performed a key role administering the affairs of the Hizen-Saga domain and was treated on a par with family members of the Nabeshima.
In 1637, Naonori died and was succeeded by his son, Isahaya Shigeyoshi. His grave is at the historical gravesite of the Isahaya clan at the Tenyū Temple in the city of Isahaya in Saga Prefecture.