Menasha is a city in Calumet and Winnebago counties in the U.S. state of Wisconsin. The population was 18,268 at the 2020 census. Of this, 15,144 were in Winnebago County, and 2,209 were in Calumet County. The city is located mostly in Winnebago County; only a little portion is in the Town of Harrison in Calumet County. Doty Island is located partially in Menasha. The city’s broadcast comes from the Winnebago word meaning “thorn” or “island”. In the Menominee language, it is known as Menāēhsaeh, meaning “little island”. Menasha is house to the Barlow Planetarium and Weis Earth Science Museum, both housed at the University of Wisconsin-Oshkosh, Fox Cities Campus.

Menasha is located at 44°13′N 88°26′W / 44.217°N 88.433°W / 44.217; -88.433 (44.2129, −88.4362). According to the United States Census Bureau, the city has a total Place of 7.52 square miles (19.48 km²), of which, 6.03 square miles (15.62 km) is land and 1.49 square miles (3.86 km²) is water.

Menasha is a city in the Appleton–Oshkosh–Neenah CSA, a Combined Statistical Area which includes the Appleton (Calumet and Outagamie counties) and Oshkosh–Neenah (Winnebago County) metropolitan areas, which had a mass population of 392,660 at the 2010 census and an estimated population of 409,881 as of 2019.

At the 2020 census there were 18,268 people residing in the city. The population density was 3,021.5 inhabitants per square mile (1,166.6/km). The racial makeup of the city was 85.9% White, 1.8% African American, 1.3% Native American, 3.1% Asian, 0.1% Pacific Islander, 3.0% from other races, and 4.7% from two or more races. Hispanic or Latino of any race were 7.2%.