The Coudekerque-Branche–Fontinettes railway runs along the English Channel and North Sea coast of France from a junction near Coudekerque-Branche station in Dunkirk to a junction near Les Fontinettes station in Calais.

It is 41.159 kilometres (25.575 miles) long and AC electrified single track for much of its length, except for the first 10 kilometres (6.2 miles) from Dunkirk, which is double track electrified with 25 kV 50 Hz in.

[2] The line was built by Compagnie du Nord-Est and opened on 10 August 1876.

Operations were transferred on 5 June 1883 to Compagnie des chemins de fer du Nord.

The first ten kilometres of the line from Coudekerque was electrified in 1962, and the marshalling yard (triage de Grande-Synthe) at Grande-Sythe was built between 1962 and 1965.