The area of present-day Imizu was part of ancient Etchū Province, and was governed during the Edo period as part of Kaga Domain.
The modern city of Imizu was established on November 1, 2005, from the merger of the city of Shinminato, the towns of Daimon, Kosugi and Ōshima, and the village of Shimo (all from Imizu District).