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 became Mosquito County, and Enterprise was named the County Seat. This large county was renamed Orange County in 1845 when Florida became a state. For the next 70 years, Orange County would split into numerous other counties. Seminole County was one of the last counties to emerge from Orange County.
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 tribe of Indians. The name "Seminole" is thought to be derived from the Spanish word cimarron, meaning "wild" or "runaway."