Weekdays, Air France
operates 2 flights from Roissy Charles de Gaulle (at 13:55
and 21:10)
and 2 flights from Paris Orly (at 9:00 and
20:55). The flight lasts about one hour.
There are also direct flights from Bordeaux, Clermont-Ferrand, Lille, Lyon, Mulhouse, Nice, Strasbourg, Toulouse.
Ryanair operates flights from London Stansted to Dinard, near St-Malo.
There are 4 TGV a day to Rennes from CDG terminal 2. The journey takes about 3 hours.
There is on average a TGV every hour for Rennes. The journey takes between 2 and 2½ hours.
There are several Thalys trains every day between Bruxelles
and Paris Gare du Nord (via Lille Europe), and several
Eurostars trains between London Waterloo and Paris Gare du
Nord.
Another possibility is to change at Lille
Europe and take a TGV to Rennes (via Roissy Charles de
Gaulle airport).