Clay County is located in the northeastern part of the U.S. state of Florida along the west bank of the St. Johns River. As of 2020, the population was 218,245 and in 2022, that number increased to 226,589, making it the third largest county in the Jacksonville metropolitan area. While most of the county is unincorporated, there are 4 municipalities with Green Cove Springs being the county seat and the unincorporated Lakeside CDP being the largest place.