Saint-Marcellin may refer to:
- Saint-Marcellin, a soft French cheese made from cow's milk
- Saint-Marcellin, Isère, a commune in south-eastern France
- Saint-Marcellin, Quebec, a parish municipality located in the Rimouski-Neigette Regional County Municipality
- Saint-Marcellin-lès-Vaison, a commune in the Vaucluse department in southeastern France