The Old Tishomingo County Courthouse was built in 1870 at a cost of $5,000 after the town of Iuka became the county seat for the newly-formed Tishomingo County. The new courthouse was built just to the south of the main town center, near to the Mineral Springs Hotel. This courthouse was a three-story Romanesque Revival building with Second Empire elements, especially in the monumental tower in the west elevation.
In 1886 the original courthouse was partially destroyed by a fire. In 1888 the surviving portion of the courthouse was restored and rebuilt by architect L. M. Weathers under the supervision of former Governor John M. Stone. By the end of 1889, the Courthouse was complete and ready for court business. For the next 80 years, the Courthouse was the center of activity in Iuka and Tishomingo County.
In 1971, the Tishomingo County Courthouse moved across town to a new modern building. The old Tishomingo County Courthouse remained empty for several decades before being occupied by the Tishomingo County Historical Society and reopened as the Old Courthouse Museum.
The Old Tishomingo County Courthouse is a two-story brick building with arched windows and doorways on the first floor and rectangular windows on the second floor. In the 1930s a WPA project erected a two-story addition on the southeast corner of the Courthouse.