Marenisco Township is a civil township of Gogebic County in the U.S. state of Michigan. The population was 1,051 at the 2000 census.
The unincorporated community of Marenisco is within the township on the Presque Isle River near the junction of U.S. Highway 2 and M-64 at 46°22′35″N 89°41′47″W / 46.37639°N 89.69639°W / 46.37639; -89.69639. Wakefield is about 15 miles northwest and Watersmeet about 27 miles southeast on US 2.
According to the United States Census Bureau, the township has a total area of 325.9 square miles (844.1 km²), of which 310.9 square miles (805.1 km²) is land and 15.0 square miles (38.9 km² or 4.61%) is water. It is the second-largest township in land area in Michigan (after McMillan Township in Luce County).