[2] The state constitutional amendment to create the county was proposed July 8, 1920, and ratified November 2.

It is named for the Seminole tribe of Native Americans, who once lived in the Chattahoochee River basin within the county, before European settlement forced their move to the Florida Everglades.

[4] The bulk of Seminole County is located in the Spring Creek sub-basin of the ACF River Basin (Apalachicola-Chattahoochee-Flint River Basin).

A tiny southeastern corner of Seminole County, all part of Lake Seminole, is located in the Lower Flint River sub-basin of the same larger ACF River Basin.

[5] As of the 2020 United States census, there were 9,147 people, 3,363 households, and 2,162 families residing in the county.