Designed by Yost & Packard of Columbus, Ohio, this Beaux Arts-styled building was completed in 1900. The building’s dome is capped by a classical figure holding the scales of justice. The Sheriff’s Residence (now the Marion County Museum) is adjacent to the Courthouse and includes the old jail.
The interior features three magnificent murals on the third floor. One depicts David Morgan of the famous Morgan clan fighting Native Americans; the others have a focus on industry and agriculture in the area. Externally, classical ornamentation includes the Corinthian order for the series of fluted columns supporting the porticoes. Within the tympanum are decorative figures of scales, an eagle with outstretched wings, a mining car, a shovel and a male figure representing justice, power, agriculture, and mining.