The Town of Delafield is located in Waukesha County, Wisconsin, United States. The population was 8,095 at the 2020 census. The City of Delafield is adjacent to the town. The unincorporated community of Buena Vista is located in the town.

Waukesha County is a county in the U.S. state of Wisconsin. As of the 2020 United States Census, the population was 406,978, making it the third-most populous county in Wisconsin. Its median income of $88,985 placed it as the only county in Wisconsin on the list of the 100 highest-income counties in the U.S. by median income as of 2020. Its county seat and largest city is Waukesha.