Ōmori Fujiyori served as a bushō during the late Muromachi and Sengoku periods.  He was the head of the Suruga-Ōmori clan and a retainer of the Ōgigayatsu-Uesugi family.  Fujiyori served as the lord of Odawara Castle in Sagami Province.

Fujiyori was born as the second son of Ōmori Ujiyori.  He was the younger brother of Ōmori Saneyori.  Saneyori died early, so, after the death of his father, Ujiyori, around 1494, Fujiyori inherited the headship of the clan.  Following the demise of Ujiyori, details regarding the status of the Ōmori clan are uncertain including with respect to the history of Fujiyori.  It appears there was internal strife between Ujiyori and a faction led by Ōmori Noriyori who earlier challenged him for headship of the clan.

According to widely-known stories in military chronicles, after the death of Ujiyori, Ise Sōzui (Hōjō Sōun) began to offer gifts, feigning friendly relations as a means to have Fujiyori let down his guard.  After permitting Sōzui to engage in deer hunting in the mountains of Hakone, Fujiyori was subject to a surprise attack by individuals pretending to be scouts for the hunt who instead attacked Odawara Castle and ousted him.  This event is commonly understood to have occurred in 1495, but, according to a letter written by Uesugi Akisada of the Yamauchi-Uesugi in 1496, he attacked the Ōmori clan at Odawara Castle only to be defeated by reinforcements from Sōun and Miura Yoshiatsu.  Therefore, it is surmised that Sōun captured Odawara Castle later, by 1501.  With respect to the capture of the castle, whether these events transpired between Fujiyori and Sōun is uncertain.

Thereafter, Fujiyori received support from Miura Yoshiatsu who was a relative, whereupon he fled to Sanada Castle in the Ōsumi District of Sagami.  In 1498, he was defeated in the ensuing battle and took his own life.  There is a theory, however, that Fujiyori continued to live thereafter and that the member of the Ōmori clan who killed himself at Sanada Castle was someone else.  According to records at the Jōkō Temple that is the family temple of the Ōmori clan in the town of Oyama in Shizuoka Prefecture, Fujiyori died in 1503 so the details of his demise remain uncertain.