Founded in 1857, Bay County is one of 83 counties in the state of Michigan. Historically, Bay County was formed from parts of Arenac, Midland, and Saginaw Counties. The city of Bay City is the county seat. With FIPS code of 17, Bay County has a population of 102,985 and area of 631 square miles (1,634 km2).
List of all cities in Bay County, MI alphabetically
| City/Town | Postal Code | Area Code |
| Auburn, MI | 48611 | 989 |
| Bay City, MI | 48706 | 989 |
| 48707 | 989 | |
| 48708 | 989 | |
| 48710 | 989 | |
| Bentley, MI | 48613 | 989 |
| Essexville, MI | 48732 | 989 |
| Kawkawlin, MI | 48631 | 989 |
| Linwood, MI | 48634 | 989 |
| Munger, MI | 48747 | 989 |
| Pinconning, MI | 48650 | 989 |
| Rhodes, MI | 48613 | 989 |
| University Center, MI | 48710 | 989 |