Seminole County is a county in the U.S. state of Florida. Located between Orange County to the south and Volusia County to the north, it is part of the Greater Orlando metropolitan area. Its county seat and largest city is Sanford. As of the 2010 Census, Seminole County's population was 422,718, a 15.75% increase from 2000.
On July 21, 1821, there were two counties that formed Florida: Escambia to the west and St. Johns to the east. In 1824, the area to the south of St. Johns County was designated Mosquito County, with its seat at Enterprise. The county's name was changed to Orange County in 1845 when Florida became a state, and over the next 70 years several other counties were created. Seminole County was one of the last to split.
Seminole County was created on April 25, 1913 out of part of the northern portion of Orange County by the Florida Legislature. It was named for the Seminole people who historically lived throughout the area. The name "Seminole" is thought to be derived from the Spanish word cimarron, meaning "wild" or "runaway."