Travelling by train between London and Barcelona is a great way to see both France and Spain, and is far more relaxing than the equivalent plane journey! Of course, it takes longer than a flight, and with the number of low-cost carriers flying between the two cities, it is unlikely to be cheaper. Nevertheless, the enjoyment of the journey has to be worth something, as does waking up feeling refreshed once your reach Barcelona.
The journey starts off in London as you board the Eurostar at St Pancras. You travel across the English Channel in style, reaching Paris in the early evening. You can choose to travel earlier if you want time to explore Paris during the day. Once in Paris, you make your way over to Gare d'Austerlitz on the Paris Metro. From there, you board the trainhotel (trenhotel) to Barcelona.
If you are trying to make the journey as quick as possible, aim for these specific services. If you would like to spend longer in Paris, feel free to catch an earlier Eurostar service. There is only one sleeper train to Barcelona a day though, so try not to miss it!
London to Barcelona by Train:
Depart London St Pancras (Eurostar): 15.02 (15.32 Sat)
Arrive Paris Gare du Nord: 18.17 (18.47 Sat)
Transfer between Paris Gare du Nord and Gare d'Austerlitz: allow one hour
Depart Paris Gare d'Austerlitz (TrenHotel): 20.37
Arrive Barcelona Franca: 08.24
Barcelona to London by Train:
Depart Barcelona Franca (TrenHotel): 21.05
Arrive Paris Gare d'Austerlitz: 09.02
Transfer between Gare d'Austerlitz and Paris Gare du Nord: allow one hour
Depart Paris Gare du Nord (Eurostar): 11.13
Arrive London St Pancras: 12.29