The Canton of Fontaine-le-Dun is a former canton situated in the Seine-Maritime département and in the Haute-Normandie region of northern France. It was disbanded following the French canton reorganisation which came into effect in March 2015. It consisted of 16 communes,^[1] which joined the canton of Saint-Valery-en-Caux in 2015.^[2] It had a total of 4,497 inhabitants (2012).^[1]

A farming area in the arrondissement of Dieppe, centred on the town of Fontaine-le-Dun. The altitude varies from 0m (Saint-Aubin-sur-Mer) to 128m (Anglesqueville-la-Bras-Long) for an average altitude of 68m.

The canton comprised 16 communes:^[1]

• Arrondissements of the Seine-Maritime department
• Cantons of the Seine-Maritime department
• Communes of the Seine-Maritime department