Delavan is a city in Walworth County, Wisconsin, United States. The population was 8,505 at the 2020 census. It is located 45 miles (72 km) southwest of Milwaukee. The city is located partially within the Town of Delavan, but the two entities are politically independent. Delavan is house to Delavan Lake which brings in a large number of tourists each year, and is also near to Lake Geneva, another popular tourist destination.

Delavan sits in the center of what was bearing in mind an inland sea. During the last Ice Age, the final glaciation, named the Michigan tongue, covered this region. The Michigan tongue descended along the area of Lake Michigan. The “Delavan lobe” of this glacier broke off, pushing southwest into the area of Walworth County.

The first humans known to inhabit the Delavan Place were Native Americans roughly 1000 BCE. Later, between 500 and 1000 CE, Mound Builders lived in what is now the Delavan Lake area. Mound Builders were of the Woodland culture. The effigy mounds they erected along the shores of Delavan Lake numbered capably over 200, according to an archeological survey finished in the late 19th century by Beloit College. Many were along the north shore of the lake where Lake Lawn Resort now stands. The Potawotomi Indians settled in the region of the lake in the late 18th century, although there were and no-one else an estimated 240 in the county. Some of their burial mounds are preserved in what is now Assembly Park.

From the mid-17th century through the mid-18th century, Delavan was allocation of “New France”. It came under British adjudicate in the Province of Quebec similar to the French and Indian War. In accordance with the Treaty of Paris (1783), it was turned beyond to the United States and became share of the newly usual Northwest Territory.