Marenisco is an unincorporated community and census-designated place (CDP) in Marenisco Township, Gogebic County, Michigan, in the United States. As of the 2010 census, the CDP had a population of 254, out of a total population in the township of 1,727. The name of the community and the township was formed by combining the first three letters from Mary Enid Scott, the wife of E. H. Scott, a timber producer.
The community is located in the western part of Marenisco Township, in the western part of Michigan's Upper Peninsula. U.S. Route 2 runs along the northern edge of the community, leading east 27 miles (43 km) to Watersmeet and west 13 miles (21 km) to Wakefield. Ironwood, Michigan, at the Wisconsin state line, is 26 miles (42 km) to the west on US 2. State highway M-64 passes through the center of Marenisco, leading south 9 miles (14 km) to the Wisconsin border.
According to the U.S. Census Bureau, the Marenisco CDP has an area of 3.4 square miles (8.9 km2), all of it land. The community is bounded to the east by the Presque Isle River, which flows to Lake Superior in northeastern Gogebic County.