Michigan is located in the eastern north-central US, and is the 3rd-largest state East of the Mississippi River. It ranks 23rd in size among the 50 states covering a total area of 58,527 sq mi (151,585 sq km).

The state includes the upper peninsula adjoining three of the Great Lakes—Superior, Huron, and Michigan—and the lower peninsula, projecting northward between Lakes Michigan, Erie, and Huron. Michigan's upper peninsula is bounded on the North and East by the Canadian province of Ontario; on the South by Lake Huron, the Straits of Mackinac separating the two peninsulas, and Lake Michigan; and on the South West and West by Wisconsin. The lower peninsula of Michigan is bordered on the North by Lake Michigan, the Straits of Mackinac, and Lake Huron; on the East by Ontario; on the South East by Ontario and Ohio. The state's geographic center is in Wexford County, 5 mi (8 km) NNW of Cadillac. Lansing is the capital of Michigan.

Among the most important islands present in Michigan are Isle Royale in Lake Superior; Sugar, Neebish, and Drummond islands in the St. Marys River; Bois Blanc, Mackinac, and Les Cheneaux islands in Lake Huron; Beaver Island in Lake Michigan; and Belle Isle and Grosse Ile in the Detroit River.