The name Tri-Cities refers to two regions in the U.S. state of Michigan. Both are located in the Lower Peninsula.
See main article: Saginaw, Midland, and Bay City Metropolitan Area.
| Greater Tri-Cities | |
| Other Name: | The Great Lakes Bay Region |
| Settlement Type: | Central Michigan |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Michigan |
| Population Density Km2: | auto |
The larger and more well known Tri-Cities is the region surrounding Saginaw, Bay City, and Midland, three cities of roughly equal medium size. This region, which is part of Central Michigan, includes much of Bay County, Saginaw County, and Midland County. These three counties make up the Greater Tri-Cities, a common term describing this region of Michigan. The region also goes by the name of the Great Lakes Bay Region.
Statistically, the region is known as the Saginaw, Midland, and Bay City Metropolitan Area, a combined statistical area composed of these three counties. Their combined population was 377,474 as of the 2020 census.
The smaller, less known Tri-Cities region lies in Western Michigan's Ottawa County, roughly west of Grand Rapids. The three municipalities are Grand Haven, Ferrysburg, and Spring Lake. The combined population of them and adjacent townships was 47,263 as of the 2020 Census.