Sault Ste. Marie is a city in the Upper Peninsula of the U.S. state of Michigan. It is the county seat of Chippewa County and is the only city within the county. With a population of 13,337 at the 2020 census, it is the second-most populated city in the Upper Peninsula, behind Marquette. It is the primary city of the Sault Ste. Marie, MI Micropolitan Statistical Area, which encompasses all of Chippewa County and had a population of 36,785 at the 2020 census. Sault Ste. Marie was settled by mostly French colonists in 1668, making it the oldest city in Michigan.

The Upper Peninsula of Michigan—also known as Upper Michigan or colloquially the U.P.—is the northern and more elevated of the two major landmasses that make up the U.S. state of Michigan; it is separated from the Lower Peninsula by the Straits of Mackinac. It is bounded primarily by Lake Superior to the north, separated from the Canadian province of Ontario at the east end by the St. Marys River, and flanked by Lake Huron and Lake Michigan along much of its south. Although the peninsula extends as a geographic feature into the state of Wisconsin, the state boundary follows the Montreal and Menominee rivers and a line connecting them.