Florida's 18th congressional district is an electoral district for the U.S. Congress, located in the Florida Heartland. In the 2020 redistricting cycle, the district was created as a new district, which includes the inland counties of DeSoto, Glades, Hardee, Hendry, Highlands, and Okeechobee, as well as most of Polk County and some of Immokalee in Collier County. The previous 18th district, located in the Treasure Coast, was instead renamed the 21st district.

Highlands County is a county located in the Florida Heartland region of the U.S. state of Florida. As of the 2020 census, the population was 101,235. Its county seat is Sebring.