Marnay may refer to:
Communes in France:
- Marnay, Haute-Saône, in the Haute-Saône department
- Marnay, Saône-et-Loire, in the Saône-et-Loire department
- Marnay, Vienne, in the Vienne department
- Marnay-sur-Marne, in the Haute-Marne department
- Marnay-sur-Seine, in the Aube department
People:
- Eddy Marnay (1920-2003), French songwriter