Midlothian (mĭdlōˈthēən) [key], council area (1993 est. pop. 79,910), 137 sq mi (356 sq km), and former county, SE Scotland. Under the Local Government Act of 1973, Midlothian was divided between the former Lothian and Borders regions in 1975. In the local government reorganization of 1996, Lothian was dissolved and the council area of Midlothian was created from part of the former territory of the county of Midlothian. The county of Midlothian was formerly known as Edinburgh or Edinburghshire.