Martinsburg South Middle School is located in historic downtown Martinsburg in the heart of the Shenandoah Valley. It was built in 1954 as Martinsburg Junior High. Classes started for 7th and 8th grades in 1955. The first principal was Granville Shirley. It became Martinsburg South Middle School in 1976 when Berkeley County adopted the middle school concept.

In 2005 renovations were completed adding a new science wing with four new science labs, new student restrooms upstairs and downstairs, a new band room, and renovations to the gym and most of the rooms and hallways. More renovations, including new office spaces and a new cafeteria are expected to begin early summer of 2006.