There are regular connections between Brest and Paris by high speed train (TGV). Leaving from Paris Montparnasse station, the journey takes on average 5hrs 40 minutes.
All seats on TGV trains are numbered and must be reserved. Prices vary depending on the time and day of departure and you are strongly advised to book in advance in order to take advantage of the cheapest fares. For example the cheapest one-way ticket to Brest is currently available at 39€, whereas a ticket bought on the day will cost at least 100€.
A low-cost coach service, Ouibus, operates between Brest and Paris. This service offers quite comfortable travel with free-wifi, air-conditioning and an on-board toilet. However, the journey from Paris takes around 10 hours. Fares vary depending on your day and date of travel, so advance booking is highly recommended.
For more information about coach schedules and fares see: