Delavan is a city in Walworth County, Wisconsin, United States. The population was 8,505 at the 2020 census. It is located 45 miles southwest of Milwaukee. The city is located partially within the Town of Delavan, but the two entities are politically independent. Delavan is home to Delavan Lake which brings in a large number of tourists each year, and is also close to Lake Geneva, another popular tourist destination.