Collier County is located in southwestern Florida against the Gulf of Mexico. Collier County contains some 2,025 square miles of land area and 280 square miles of water surface. The county seat is Naples.

Created in 1923 from Lee County, Collier County was named for Barron Collier, a real estate developer and advertising mogul from New York City. Collier came down from New York with his wife Juliet on vacation and ended up buying a huge chunk of land in the area and then building the Tamiami Trail. The southeastern portion of Collier County is within the Big Cypress National Preserve while the southern coastal region of the county is within Everglades National Park. Ten Thousand Islands National Wildlife Refuge and the Florida Panther National Wildlife Refuge are also in Collier County.