Uminaka-hachimangū, Shinto shrine in Japan

Uminaka-hachimangū is a Shinto shrine in Shibasaki-chō, Choshi, Chiba Prefecture. Its main hall (honden) is a prefectural-designated tangible cultural property. The shrine enshrines Hachiman Ōkami, Hime Ōkami and Empress Jingū, and also houses an Inari Ōkami. According to shrine tradition, it began in 807 when a statue of Hachiman Daibosatsu was placed here after a white heron repeatedly cried and descended at the site.

According to shrine tradition, the origin dates to 807 (Daidō 2), when a white heron repeatedly cried and a statue of Hachiman Daibosatsu was enshrined on this spot. The shrine also claims to have received a divided Hachiman spirit from Usa Hachiman and was called Sōsha Hachimangū or Shibazaki Hachimangū. After the Battle of Ishibashiyama, Minamoto no Yoritomo prayed here; when he established the Kamakura shogunate, the shrine was moved to its present site and rebuilt. In the Middle Ages the Chiba, Uminaka and Tō clans venerated and donated to it, and the Tokugawa shogunate issued vermilion-seal documents; in the Edo period it held 30 koku of shrine land as the sōchinju of more than 60 villages of Uminaka District.

The shrine is also known as Sōsha Hachimangū and Shibasaki Hachimangū, and in the Edo period it served as sōchinjū of more than sixty villages of Unakami District. Inari Ōkami is worshipped here alongside Hachiman. The shrine's name, Uminaka, is written with the characters for "sea" and "within".

The shrine stands in Shibasaki-chō, Choshi, near the Pacific coast at the eastern tip of Chiba Prefecture. The grounds are entered freely and the main hall, a prefectural tangible cultural property, can be viewed from outside. As an active place of worship, visitors keep to the paths and avoid the precinct during rites.

The shrine's origin story tells of a white egret that cried repeatedly in 807 and dropped a statue of Hachiman Daibosatsu on this spot, where it was then enshrined. The shrine was also moved to its present location when Minamoto no Yoritomo founded his shogunate in Kamakura, after he had prayed here following the Battle of Ishibashiyama.