The railway from Saint-Denis to Dieppe is a French 161-kilometre long railway line, that connected Paris to Dieppe on the English Channel coast.

The part between Gisors and Serqueux was closed from 2009 to 2013, and the part between Serqueux and Arques-la-Bataille has been demolished.

The Saint-Denis–Dieppe railway begins in the northern suburbs of Paris, near the Saint-Denis station, where it branches off the railway from Paris to Lille.

It runs in generally northwestern direction, passing through Pontoise, Gisors, Gournay-en-Bray and Serqueux, where it crosses the Amiens–Rouen railway.

The now demolished section beyond Serqueux passed through Neufchâtel-en-Bray, and followed the river Béthune downstream until it reached its terminus Dieppe station.