Ōmori Noriyori served as a bushō during the late Muromachi and Sengoku periods.  He served as the head of the Ōmori clan and as the lord of Odawara Castle in Sagami Province.  Noriyori was a retainer of the Kamakura kubō (Ashikaga Mochiuji followed by Ashikaga Shigeuji).

Noriyori was born as the son of Ōmori Yoriharu.  Following after his father, Noriyori served as an influential kokujin, or provincial landowner, on behalf of the Kamakura kubō.  During the Eikyō Conflict in 1438, Noriyori supported Ashikaga Mochiuji (the fourth Kamakura kubō) and, together with his younger brother, Ōmori Sanetake (the Provisional Steward of Hakone), participated in the Battle of Hakoneyama.  Even after the death and defeat in battle of Mochiuji, the Ōmori clan maintained their power.  At the Battle of Yūki, as Noriyori attempted to deploy to Yūki Castle in Shimōsa Province, the Suruga-Imagawa and Kanbara clans guarded Kamakura.  Noriyori developed Odawara Castle and seized neighboring territory, but, after Ashikaga Shigeuji fled to Koga and the Ōgigayatsu-Uesugi clan became powerful in Sagami, he came into conflict with his younger brother, Ōmori Ujiyori, who supported the Ōgigayatsu-Uesugi.  During the Revolt of Nagao Kageharu, Noriyori aligned with Kageharu and holed-up in Hiratsuka Castle in Sagami.  He was then attacked by Ōta Dōkan whereupon, together with his son, Ōmori Shigeyori, he fled into the mountains of Hakone and fell into ruin.