Massac may refer to several places in the United States:

• Massac, Kentucky
• Massac County, Illinois
• Fort Massac, Massac County, Illinois

Massac is the name or part of the name of several communes in France:

• Massac, Aude, in the Aude département
• Massac, Charente-Maritime, in the Charente-Maritime département
• Massac-Séran, in the Tarn département
• Massiac, Communes of the Cantal département, is the origin of the "Massac" name in Illinois.