Lafayette County, sometimes spelled La Fayette County, is a county located in the U.S. state of Wisconsin. It was part of the Wisconsin Territory at the time of its founding. As of the 2020 census, the population was 16,611. Its county seat is Darlington. The county was named in honor of the Marquis de Lafayette, the French general who rendered assistance to the Continental Army in the American Revolutionary War. The courthouse scenes from the 2009 film Public Enemies were filmed at the Lafayette County Courthouse in Darlington.

The Territory of Wisconsin was an organized and incorporated territory of the United States that existed from July 3, 1836, until May 29, 1848, when an eastern portion of the territory was admitted to the Union as the State of Wisconsin. Belmont was initially chosen as the capital of the territory. In 1837, the territorial legislature met in Burlington, just north of the Skunk River on the Mississippi, which became part of the Iowa Territory in 1838. In that year, 1838, the territorial capital of Wisconsin was moved to Madison.