By TGV from Paris Montparnasse. St Brieuc is on the TGV Ouest line between Paris and Brest. There are about 10 trains a day. In some cases, you may need to change trains in Rennes. The train ride takes about 3 hours.
By car
By car
St Brieuc is on the N12 expressway about 90 min from Rennes. Watch out for the speed cams on the bridges.
By ship
By ship
You can transit through Roscoff, 2 h by car to the west. or Saint-Malo, 90 min to the east. Brittany Ferries runs overnight car and passenger ferries from southern English ports of Portsmouth and Plymouth.