Map of Michigan Counties

Michigan has 83 counties, the 15th-highest count among the 50 states. Of these, 68 are on the Lower Peninsula and 15 are on the Upper Peninsula, north of the Straits of Mackinac. Michigan has had 83 counties since 1897, when Isle Royale County was merged into Keweenaw County. Dickinson County, created in 1891, is the newest county. Michigan numbers its counties alphabetically, from Alcona County as No. 1 to Wexford County as No. 83. Together the 83 counties had 10,140,459 residents on July 1, 2024, according to US Census Bureau estimates.

Marquette County is the largest county in Michigan by land area, with 1,809.1 square miles (4,686 km²) in the US Census Bureau's 2026 Gazetteer Files. It lies on Lake Superior in the central Upper Peninsula, and its 67,979 residents in 2024 make it the most populous county north of the Straits of Mackinac. Counting water changes the answer. In the same 2026 files, Keweenaw County has only 540.1 square miles (1,399 km²) of land but 5,426.2 square miles (14,054 km²) of water, mostly Lake Superior, for a total of 5,966.3 square miles (15,453 km²). Benzie County has the least land, at 319.7 square miles (828 km²).

Wayne County is the most populous county in Michigan, with 1,771,063 residents on July 1, 2024, according to US Census Bureau estimates. Wayne alone holds about 17.5% of Michigan's 10,140,459 residents. Detroit, the state's largest city, is the county seat, and Dearborn and Livonia are also in Wayne County. Oakland County, to the north, ranks second with 1,296,888, and Macomb County is third with 886,175. Those three counties are home to 39% of Michigan's residents. The gap between the top two is shrinking. Wayne's estimate fell by 18,592 between 2020 and 2024, while Oakland's grew by 24,362. Kent County, home to Grand Rapids, is fourth with 673,002.

Lansing, the capital of Michigan, is mostly in Ingham County, and parts of the city reach west into Eaton County and north into Clinton County. The State Capitol stands in the Ingham County part of the city, and Michigan State University is next door in East Lansing, also in Ingham County. Lansing is not a county seat, though. Ingham County's seat is Mason, a small city south of Lansing, and Eaton County's seat is Charlotte. Ingham County had 290,427 residents in the US Census Bureau's July 2024 estimates, eighth among Michigan's 83 counties, on 556.1 square miles (1,440 km²) of land, per the 2026 Gazetteer Files. Eaton County had 109,494.

The Upper Peninsula of Michigan has 15 counties: Alger, Baraga, Chippewa, Delta, Dickinson, Gogebic, Houghton, Iron, Keweenaw, Luce, Mackinac, Marquette, Menominee, Ontonagon and Schoolcraft. The other 68 are on the Lower Peninsula. Together the 15 Upper Peninsula counties cover 16,378.4 square miles (42,420 km²) of land, about 29% of the state total in the Census Bureau's 2026 Gazetteer Files, but they had only 304,430 residents in July 2024, about 3% of Michigan's population. Marquette County is the largest and most populous of them, with 67,979 people. Keweenaw County, at the peninsula's northern tip, is the least populous county in the state, with 2,161. The Mackinac Bridge links Mackinac County to Emmet County on the Lower Peninsula.

Four Michigan counties use Central Time: Gogebic, Iron, Dickinson and Menominee. All four are in the western Upper Peninsula and share a border with Wisconsin, which is also on Central Time. The other 79 counties use Eastern Time, including all 68 on the Lower Peninsula and Upper Peninsula counties such as Marquette, Houghton and Chippewa. Both zones observe daylight saving time. The four Central Time counties had 74,971 residents combined in the US Census Bureau's July 2024 estimates and cover 4,073.2 square miles (10,550 km²) of land in the 2026 Gazetteer Files. Dickinson County, whose seat is Iron Mountain, is the largest of the group by population at 25,995, and Iron County is the smallest at 11,709.

Dickinson County is the newest county in Michigan. The state legislature created it in 1891 from parts of Iron, Marquette and Menominee counties and named it for Don M. Dickinson, a Detroit lawyer who served as US Postmaster General. Iron Mountain is its county seat. Michigan became the 26th state on January 26, 1837, and most of its counties were organized during the 19th century as settlement moved north. The last change to the number of counties came in 1897, when Isle Royale County was merged into Keweenaw County, which still includes Isle Royale National Park. Michigan has had 83 counties ever since. Dickinson County had 25,995 residents in July 2024, per Census Bureau estimates.

The Upper Peninsula is part of Michigan because of how the Toledo War ended. That 1835 to 1836 dispute between Michigan Territory and Ohio was over the Toledo Strip, a band of land along what is now the Ohio border. Congress made statehood depend on Michigan giving the strip to Ohio, and in exchange Michigan received the western Upper Peninsula. The eastern end, around Mackinac Island and Sault Ste. Marie, already belonged to the territory. Michigan accepted the terms in December 1836 and became the 26th state on January 26, 1837. Toledo is now in Lucas County, Ohio. Today the Upper Peninsula's 15 counties hold 304,430 people, about 3% of the state, in Census Bureau estimates for 2024.

A custom map of Michigan starts from this 83-county map in the Ultimaps editor, which is free and works without an account. To highlight a few counties, such as a sales region around Grand Rapids, select each one and pick a fill color. For data like customer counts or 2024 population, import a spreadsheet listing each county with its number, and the editor builds a color scale and legend from the values. Drop pins on individual sites, for example campuses in Ann Arbor and East Lansing. Style options cover the palette, borders, labels and title. Standard PNG exports are free and include a small Ultimaps credit, while the Pro plan covers high-resolution PNG, SVG and PDF.