Built in: 1625
Tozawa Masamori, the daimyo of Hitachi-Matsuoka Domain was moved to Dewa Region in September 1622 following the suppression of the Mogami clan by the Tokugawa Government and gained an increase in revenues to 60,000 koku. His new territory extended over all of what is now Mogami District and a portion of Murayama District in what is now Yamagata Prefecture. Finding the old hill-top Sakenobe Castle to be too small and inconveniently located, he petitioned the shogun government for permission to construct a new castle in the flatlands with the main bailey, secondary bailey to the south, all surrounded by a third bailey and wet moats.
In 1636, the donjon was destroyed in a fire and was never reconstructed
In 1868, during the Boshin War of the Meiji restoration, the castle was the site of the Battle of Shinjo. Following the defection of Kubota Domain from the Ōuetsu Reppan Domei, Shinjo Domain soon followed suit. Shinjo Domain was then invaded by the armies of neighboring Shonai Domain, and in the subsequent battle, Shinjō Castle and much of its surrounding castle town were destroyed.