Mosinee is a city in Marathon County, Wisconsin, United States. It is part of the Wausau, Wisconsin Metropolitan Statistical Area. The population was 4,063 at the 2000 census. The 2006 population estimate is 4,186 according to the Wisconsin Department of Administration Demographic Services Center.
Mosinee is located at 44°47'30" North, 89°42'19" West (44.791709, -89.705301).
According to the United States Census Bureau, the city has a total area of 8.6 square miles (22.2 km²), of which, 7.8 square miles (20.2 km²) of it is land and 0.8 square miles (2.0 km²) of it (9.11%) is water.