Mary Long

Mary Long may refer to:

• Mary Long (soccer) (born 2007), American soccer player
• Mary Beth Long (born 1963), American businesswoman and former U.S. government official
• Mary Elitch Long (1856–1936), one of the original owners of Elitch Gardens in Denver, Colorado
• Mary "Polly" Long, first wife of Tobias Lear V
• "Mary Long", a song by Deep Purple from their 1973 album Who Do We Think We Are