Miyauchi (宮内町, Miyauchi-chō) was a town located in Higashiokitama District, Yamagata Prefecture, Japan.

On April 1, 1967, Miyauchi was merged into the expanded city of Nan'yō and thus no longer exists as an independent municipality.

It was raised to town status on February 1, 1955, by merging with the villages of Urushiyama, Yoshino, and Kaneyama.

The festival's highlight is a series of human dolls made from locally grown chrysanthemums.

The Hygeia Park onsen, which contains a small Isabella Bird Memorial Exhibition, is also situated in the town