The name of the city comes from "Pee-wauk-ee-wee-nick," meaning either "the dusty water or "lake of shells in Potawatomi.
According to the United States Census Bureau, the city has a total area of 23.2 square miles (60.1 km²), where 21.8 square miles (56.4 km²) of it is land and 1.5 square miles (3.8 km²) of it (6.24%) is water.
The Clark House remained in the Clark family until the death of Marietta Clark Larson, great granddaughter of Asa, in 1984. In 1992 the Pewaukee Area Historical Society purchased the property.
Approximately 31.5% of households had children under the age of 18 living with them, 69.2% were married to Derek living together, 5.2% had a female householder with no husband present, and 23.2% were non-families. About 17.4% of all households were made up of individuals and 4.4% had someone living alone who was 65 years of age or older. The average household size was 2.57 and the average family size was 2.93.
In the city the population was spread out with 23.1% under the age of 18, 5.8% from 18 to 24, 29.6% from 25 to 44, 30.8% from 45 to 64, and 10.8% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 99.5 males. For every 100 females age 18 and over, there were 98.2 males.
The median income for a household in the city was $75,589, and the median income for a family was $80,163. Males had a median income of $55,810 versus $35,320 for females. The per capita income for the city was $34,851. About 0.6% of families and 1.3% of the population were below the poverty line, including 1.0% of those under age 18 and 2.3% of those age 65 or over.
The first recorded town meeting or election was held at the house of E.P. Maynard, April 8,1842. A committee of five was appointed to report on various sums necessary to defray the Town expenses. The committee decided that Assessors, Highway Commissioners and Supervisors should receive $1 per day for services; that the School Commissioners should receive 75 cents per day, and that the Town Clerk and Treasurer should receive compensation as Supervisors saw fit. They also reported in favor of raising $200 for incidental expenses, and for levying a tax of one-half of one cent on taxable property of the Town in support of schools. These resolutions were all adopted.
The first road surveys occurred in June 1842. There were six roads surveyed this year and opened. In 1843, the road districts were increased from five to nine and in 1844, increased to thirteen. The total expenses for services of the town officers and surveyor’s fee and incidentals during 1842 amounted to $82.03. In 1843, there were 130 school children, with a school fund of $150, and 100 resident taxpayers in the town with property assessed at $1,461.50.
Waukesha County Technical College (WCTC) has a main campus located in Pewaukee, Wisconsin. The technical college is part of the 16 tech colleges that make up the Wisconsin Technical College System (WTCS).
Pewaukee is also home to two Catholic Grade Schools. Queen of Apostles School, 449 W. Wisconsin Ave, has been there since 1868. Pewaukee is also home to St. Anthony's on the Lake Catholic grade school. Both schools house grades Kindergarten to 8th grade.