Sheridan is a city in the U.S. state of Wyoming and the county seat of Sheridan County. The city is located halfway between Yellowstone Park and Mount Rushmore by U.S. Route 14 and 16. It is the principal town of the Sheridan, Wyoming, Micropolitan Statistical Area which encompasses all of Sheridan County. The 2020 census put the city's population at 18,737, making it the 6th most populous city in Wyoming.