Fort Atkinson is a city in Jefferson County, Wisconsin, United States. It is on the Rock River, a few miles upstream from Lake Koshkonong. The population was 12,368 at the 2010 census.
Fort Atkinson was named after General Henry Atkinson, the commander of U.S. forces in the area during the Black Hawk War (1832) against a mixed band of Sauk, Meskwaki and Kickapoo peoples. The city developed at the site of Fort Koshkonong, which was used during that war. A replica of the original 1832 stockade has been built just outside town, although not at the original site. The fort was located to control the confluence of the Rock and Bark rivers.
The settlement grew rapidly in the mid-19th century, after the migration of pioneers from the east, especially New York State and the northern tier. They were among the many migrants carrying New England Yankee culture west across the northern tier of states.
The history and natural history of Fort Atkinson and the surrounding area are presented at the Hoard Historical Museum and National Dairy Shrine Museum. William Dempster Hoard founded the nationally distributed dairy farm magazine Hoard's Dairyman in Fort Atkinson in 1885.