Lutherville-Timonium was a census-designated place (CDP) in Baltimore County, Maryland, United States, for the 2000 census. At that time the population was 15,814. For the 2010 census the area was split into two CDPs, the unincorporated communities of Lutherville and Timonium. Within its borders lies the Lutherville Historic District. The Maryland State Fair is held in Timonium each year near Labor Day. According to the United States Census Bureau, the CDP had a total area of 7.4 square miles (19.1 km²), all of it land.