Honjō Saneyori served as a bushō during the Sengoku and Azuchi-Momoyama periods.  Saneyori was a retainer of the Nagao clan (Uesugi clan), the deputy military governor and sengoku daimyō family of Echigo Province.  He served as the lord of Tochio Castle in the Koshi District of Echigo.

From an early age, Saneyori acted as a deputy to Nagao Kagetora (later known as Uesugi Kenshin).  In addition, he served as a magistrate and was counted among the Seven Generals of the Uesugi.  Saneyori was also called Honjō Yoshihide.

As the lord of Tochio Castle, Saneyori served the Nagao clan from the era of Nagao Harukage.  However, he noticed the potential of Kagetora from an early age, and soon welcomed him to Tochio Castle to become a close associate.

At the age of fourteen, Kagetora headed out to suppress a rebellion by kokujin, or provincial landowners, in Echigo.  Kagetora went on this mission in lieu of his older brother, Harukage, who was in frail health.  In this event, Saneyori contributed as his deputy.  During Kagetora’s early years, Saneyori served as his instructor of military studies, contributing significantly to his development.

Saneyori was deeply trusted by Kenshin, and, together with Naoe Kagetsuna, was one of the close associates of Kenshin granted significant authority within the family.  In 1561, Saneyori also participated in the Fourth Battle of Kawanakajima.

In 1556, in a territorial dispute between retainers of the Uesugi named Shimodaira Yoshinaga and Ueno Ienari, Saneyori sided with Ienari while Ōkuma Tomohide supported Yoshinaga.  With both of them carrying responsibilities to direct affairs in the clan, Saneyori and Tomohide were rivals within the Uesugi.  The dispute intensified as the band of retainers split into two rival factions.  Once the Takeda and Ashina clans became involved, the situation escalated into a military confrontation.  Kagetora then absconded from Kasugayama Castle, declaring his intention to enter the priesthood.  This event is known as the Priesthood Disturbance.

Tomohide, together with the Ashina army, launched an onslaught to defeat Ienari.  Saneyori then submitted a written pledge to Kagetora stating that, going forward, the band of retainers would reverently serve without intentions of duplicity whereupon the disturbance ended.

After his defeat, Tomohide fled to the protection of Takeda Shingen and, thereafter, served in important roles for the Takeda clan.

He is believed to have died in 1575, but, under other theories, he continued to live.  There is also a theory that Saneyori martyred himself after the death of Kenshin in 1578.