Kaycee is a town in Johnson County, Wyoming, United States. The population was 263 at the 2010 census. It is home to a museum that preserves the cattle ranching heritage of the area, especially the history of the Johnson County War.

Kaycee was incorporated in 1906 after the establishment of a small post office and general store. The town was named after the brand "KC" used by its earliest homesteader, John Nolan. The government required the name to be spelled out resulting in "Kaycee". The town is now home to three churches, two bars, one restaurant, one store, one museum, one k-12 school, and not a single stoplight.