Shōnai (庄内町, Shōnai-machi) is a town located in Yamagata Prefecture, Japan.

Mount Gassan, the highest of the Three Mountains of Dewa is at the intersection of the borders of Shōnai, Tsuruoka, Ōkura and Nishikawa.

Shōnai has a humid continental climate (Köppen climate classification Cfa) with large seasonal temperature differences, with warm to hot (and often humid) summers and cold (sometimes severely cold) winters.

After the start of the Meiji period, the area became part of Higashitagawa District, Yamagata Prefecture.

Karikawa merged with the neighboring villages of Kiyokawa and Tachiyazawa on October 1, 1954, and was renamed Tachikawa.