The Brown County Jail is located in the 200 Court Street, Room #1, Mt. Sterling, IL, 62353, and run by the Brown County county Sherriff Department. The Brown County Jail, Illinois is managed daily with a staff of around 140 personnel, including dispatchers, deputies, administrators, clerks, etc. Looking for an inmate at the Brown County Jail? You're in the right place! This jail is set to serve inmates 18 and older. Located in Nashville, Indiana, this jail services the city of Nashville, along with the other cities in Brown County. Inmates that are in this jail are usually only here for a short period of time before they are moved onto another jail or released. Visiting with an.