Jion-ji (慈恩寺), (山号 宝珠山; Sangō Zuihō-zan) is a major Buddhist temple located in the city of Sagae, in Yamagata Prefecture, Japan.

The temple has been a place for pilgrimage for centuries, and is designated as a National Historic Site in 2014[1] It occupies a mountain overlooking the Yamagata basin, and its main gate is at an altitude of 146 meters.

According to temple tradition, it was founded in 724 AD by the wandering holy monk Gyōki, by order of Emperor Shomu to spread Buddhism in remote Dewa Province.

During the Kamakura period, Sagae shōen passed to Ōe no Hiromoto, one of the main retainers of Minamoto no Yoritomo, and Jion-ji became a bodaiji of the Oe clan.

During the Edo Period, the temple was the largest in Dewa Province and had 48 chapels in three mountains and extensive estates for its upkeep.