Seminole County is a county located in the U.S. state of Florida. It is located in the central part of Florida, and its county seat is Sanford. Seminole County was created on April 25, 1913 and was named for the Seminole tribe of Indians. The name "Seminole", the Spanish word cimarron, meaning "wild" or "runaway." Seminole County has a total area of approximately 345 square miles of which 89% is land and 11% water. As of the 2000 census, there were 365,196 people, 139,572 households, and 97,281 families residing in Seminole County, FL.