Thermopolis is a town in Hot Springs County, Wyoming, United States. As of the 2000 census, the town population was 3,172.

As might be expected from its name and the name of its county, Thermopolis is home to numerous natural hot springs, in which mineral-laden waters are heated by geothermal processes. It claims the world's largest mineral hot springs as part of Hot Springs State Park. The springs are open to the public for free as part of an 1896 treaty signed with the Shoshone and Arapaho Indian tribes.

The town is also home of the Wyoming Dinosaur Center, a private organization that conducts paleontology digs in the area.