The Bay City Downtown Historic District is a primarily commercial historic district, located in Bay City, Michigan and roughly bounded by the Saginaw River, Second Street, Adam Street, and Center Avenue.

The initial commercial development in Bay City, in the 1850s and 1860s, occurred along North Water Street, adjacent to the lumbering businesses along the river.

Third Street, linked to West Bay City via a bridge over the river, also became an important commercial artery, as did Center Avenue.

[2] The Bay City Downtown Historic District consists of 91 structures: 90 of which are commercial, and one government building.

The district occupies about 16-1/2 square blocks in the northwest portion of Bay City's downtown.