Giant Food Stores, LLC is an American supermarket chain that operates stores in Pennsylvania, Maryland, Virginia and West Virginia under the names of Giant and Martin's. Giant is a subsidiary of Netherlands-based Ahold. Giant Food Stores are often referred to as Giant-Carlisle to distinguish it from sister company Giant-Landover. A big difference between Giant of Landover and Giant of Carlisle is that the Landover Company is unionized while Giant of Carlisle is non union with the exception of stores in the Lewistown and Philadelphia areas of Pennsylvania.