Collier County is a county in the U.S. state of Florida. As of the 2020 census, its population was 375,752; an increase of 16.9% since the 2010 United States Census. Its county seat is East Naples, where the county offices were moved from Everglades City in 1962. Collier County comprises the Naples–Marco Island Metropolitan Statistical Area, which is included in the Cape Coral-Fort Myers-Naples Combined Statiscal Area.