Ishimaki-jinja, Shinto shrine in Japan

Ishimaki-jinja is a Shinto shrine in Ishimaki-cho, Toyohashi, split into two parts: an upper shrine (Okumiya) on the mid-slope of Mount Ishimaki and a lower village shrine (Satomiya) in the valley below. It is a soshin-sha, formerly ranked as a gosha and counted as the fourth shrine of Mikawa Province, dedicated to Ōnamuchi-no-mikoto.

The founding date is unknown; tradition holds that the okumiya on the slope of Mount Ishimaki dates to the reign of Emperor Kōan and the satomiya in the valley to the reign of Empress Suiko. Mount Ishimaki itself was likely the original object of worship. Because the shrine stood on the demon gate of Yoshida Castle, successive castle lords venerated it from the time the castle was built.

The shrine is dedicated to Ōkuninushi, a god associated with health and happiness in local tradition. Visitors come to pray for their families, leave offerings, or tie wish papers called omikuji, showing how this place remains woven into everyday life.

The shrine is typically open from early morning until evening, allowing flexible visits throughout the day. A small parking area is nearby, and a water basin for hand-washing stands as a traditional purification practice before prayer.

The shrine has two parts: the upper okumiya on the slope of Mount Ishimaki and the lower satomiya in the village. The okumiya hosts the Kudagayu festival, held around early February, when the priest cooks rice porridge and steams 18 reed tubes marked with crop names; the state of the porridge inside each tube is read to forecast that year's harvest.