Midlothian is an unincorporated community and census-designated place in Allegany County, Maryland, United States; at one time it was called Midlothian Junction. As of the 2010 census it had a population of 320. Its ZIP code is 21543. Midlothian is located 2 miles southwest of Frostburg and is adjacent to Exit 33 of Interstate 68. The community sits along the eastern base of Big Savage Mountain. Also known as Midlothian Junction, it has a population of 320 in 2010.