Jefferson County, named for the nation’s third President, was founded in 1827. A county seat was specially created, including a central courthouse square, in 1828 and named for Jefferson"s mountaintop home at Monticello. (Similarly, an early county seat of Washington County was called "Mt. Vernon.") 

The first sessions of court were held at the log home of early settler John G. Robison, which also served as general store and post office. An official courthouse, also built of logs, was later erected in the town square. A more permanent structure was begun in 1834 but, owing to a dearth of funds, not completed until 1841. This was described as a two-story wooden structure "of plain and dignified design," with a veranda running around the second floor. "Here in later years the champion chess-players were wont to gather and engage in friendly warfare, while enjoying the cool shade of beautiful surrounding live oaks."  Most of these oaks, save one great spreading tree to the south, were lost when the 1841 courthouse was replaced. The building also included a bell tower which "proved too great a temptation to certain young lads of Monticello who, when the night watchman was engaged on far duty, were enabled to tie a purloined calf to the bell rope and then, safely hidden, enjoy the anathemas hurled against them by irate citizens who had risen from their beds and rushed to the square to investigate."

The current Jefferson County Courthouse, designed by E. C. Hosford, dates from 1909. Over the doors is featured the motto Suum Cuique, meaning "To Each His Own" but (according to Hampton Dunn) locally translated as "Sue ‘Em Quick."