Ishinomaki is in northeastern Miyagi Prefecture. The city borders on Matsushima Bay to the south and Kesennuma Bay to the north, with the Kitakami Mountains to the west. Its coastline forms part of the Sanriku Fukkō National Park, which stretches north to Aomori Prefecture. Ishinomaki includes Tashirojima (also known as Cat Island), Ajishima, and Kinkasan, three islands off the south coast of Oshika Peninsula.