Saint-Martin-en-Campagne is a former commune in the Seine-Maritime department in the Normandy region in northern France.

On 1 January 2016, it was merged into the new commune of Petit-Caux.

[2] A coastal farming village situated in the Pays de Caux, at the junction of the D113, D313 and the D925 roads, some 5 miles (8.0 km) east of Dieppe.

Huge chalk cliffs rise up over a pebble beach and overlook the English Channel.

The Penly Nuclear Power Plant is also sited in this commune.