The Culpeper County Sheriff's Office says the fire started around 9:15 a.m. inside a clothes dryer in a laundry room on the jail's second floor.
Deputies evacuated 81 inmates to the courthouse while firefighters put out the flames.
The inmates were returned to the jail about four hours later.
A deputy who tried to put out the fire was taken to the hospital for smoke inhalation. No other injuries are reported and the damage was minimal.
Sign up to receive NBC29 news and weather updates in your inbox daily.