Grafton is a town in Ozaukee County, Wisconsin, United States. The population was 4,132 at the 2000 census. The Town of Grafton is located about 20 miles north of downtown Milwaukee on the shore of Lake Michigan. It is east of the village of Grafton and the Town of Cedarburg, south of the Town of Port Washington, and north of the city of Mequon. The unincorporated communities of Lakefield, and Ulao are located in the town.
Historically, one of the more important settlements was the community of Ulao, Wisconsin. It was located at the eastern end of the road which became State Highway 60.
The Town of Grafton was the site of Camp Hindenburg, owned and operated by the pro-Nazi German American Bund from the late 1930s through the outbreak of World War Two. In 1940, Camp Carl Schurz, operated by the anti-Bund Wisconsin Federation of German-American Societies, was opened a mile away.
According to the United States Census Bureau, the town has a total area of 21.4 square miles (55.5 km²), of which, 19.8 square miles (51.3 km²) of it is land and 1.6 square miles (4.1 km²) of it (7.47%) is water.
The Kevich Light is located in the town.
As of the census of 2000, there were 4,132 people, 1,569 households, and 1,241 families residing in the town. The population density was 208.5 people per square mile (80.5/km²). There were 1,608 housing units at an average density of 81.1 per square mile (31.3/km²). The racial makeup of the town was 98.02% White, 0.34% Black or African American, 0.22% Native American, 0.48% Asian, 0.10% Pacific Islander, 0.34% from other races, and 0.51% from two or more races. 1.11% of the population were Hispanic or Latino of any race.