Collier County is a county located in the U.S. state of Florida. Its county seat is Naples. Collier County was created in 1923 and named for Barron Collier, a New York City advertising mogul and real estate developer. Collier County is the sole county in the Naples-Marco Island Metropolitan Statistical Area. Collier County has a total area of approximately 2,305 square miles of which 88% is land and 12% water. As of the 2000 census, there were 251,377 people, 102,973 households, and 71,257 families residing in Collier County, FL.