The Chemins de fer départementaux du Finistère were a metre gauge railway system in northwest Brittany, France. It was opened in stages between 1893 and 1907, and closed in 1946. The system had a total extent of 214 kilometres (133 mi).

The Réseau Breton (RB) is a 1,435 mm, standard gauge, and former 1,000 mm, metre gauge, railway in Finistère, France, with a few kilometres of line in Côtes d'Armor, Ille-et-Vilaine and Morbihan. The hub of the system was Carhaix. The metre gauge lines were built with the capacity to be easily converted to standard gauge if necessary.