The Marathon County Fairgrounds are located in Wausau, Wisconsin. In 1980, the site was added to the National Register of Historic Places.
The county fair, now known as the Wisconsin Valley Fair, has been held at the site since 1868. It features a stock judging pavilion (pictured) that was designed by Alexander C. Eschweiler and built in 1921. Other features on the site include a carousel, a kids' train, a curling club and campgrounds.