Jackson County is a county located in the "Panhandle" of the U.S. state of Florida, on its northwestern border with Alabama. As of the 2020 census, the population was 47,319. Its county seat is Marianna.

Jackson County was created by the Florida Territorial Council in 1822 out of Escambia County, at the same time that Duval County was organized from land of St. Johns County, making them the third and fourth counties in the Territory. The county was named for Andrew Jackson, a General of the War of 1812, who had served as Florida's first military governor for six months in 1821. Jackson County originally extended from the Choctawhatchee River on the west to the Suwannee River on the east. By 1840 the county had been reduced close to its present boundaries through the creation of new counties from its original territory, following an increase of population in these areas. Minor adjustments to the county boundaries continued through most of the 19th century, however.

There were no towns in Jackson County when it was formed. The first county court met at what was called "Robinson's Big Spring" (later called Blue Springs) in 1822 and then at the "Big Spring of the Choctawhatchee" in 1823. The following year the county court met at "Chipola Settlement", which is also known as Waddell's Mill Pond.^{[citation needed]}

The forced labor of enslaved African Americans allowed European Americans to develop this area of Florida as part of the plantation belt in the antebellum years. Cotton was cultivated as a commodity crop by large workgangs, and Florida became a slave society.

Gradually towns were developed. In January 1821, Webbville was established as the first town in Jackson County. It was the first designated as the county seat.

Marianna was founded in September 1821 by Robert Beveridge, a native of Scotland. It developed about 9 miles (14 km) southeast of Webbville. About 1828, Beveridge and other Marianna settlers went to Tallahassee to lobby the state legislature to move the county seat to Marianna.

They enticed the Florida Legislature with offers of free land, and to pay locally to construct a county courthouse and develop a related public square. They donated an additional $500 to purchase a quarter section of land to be sold at public auction as a way to finance the new government, if the county seat was moved to Marianna.

Beveridge and his supporters succeeded in their civic bribe. Marianna became the de facto county seat of the county justice and civil authority, although it was never officially proclaimed as such. Marianna began to grow and prosper when the county government moved into the new courthouse in 1829. It became the market and court town for the rural county.