Iwanai (岩内町, Iwanai-chō) is a town located in Shiribeshi Subprefecture, Hokkaido, Japan.

Unlike many Hokkaido towns, it predates the Meiji Restoration, having started as a seasonal fishing location c. 1450, and developing into a year-round village in the mid-18th century.

Citizens of Iwanai whose families have been native for many generations have a peculiar "fisherman" accent to their Japanese, distinct to others living in the region.

Modern Iwanai is much more Western in style, although there are still extensive Shinto shrines and Buddhist temples intact or rebuilt in the traditional fashion.

His marks are "nejiri hachimaki" (a traditional Japanese headband), a "kuroi nagagutsu" (a black boot) and his mouth and always carries an asparagus as a weapon.