If you'd like to visit San Sebastian from Bilbao as part of a guided tour, check out this Day Trip to San Sebastian and Biarritz (book direct)
Note: these times and prices are subject to change and are intended as guidance only. Please check the websites for current prices and timetables.
Bilbao to San Sebastian by TrainThe Basque Country has its own local train network, called Euskotren. It is very cheap and there are departures every hour (more often if you don't mind changing trains) but it is very slow - taking about 2h30 to get from Bilbao to San Sebastian. See a Euskotren map.
The main rail network, RENFE, doesn't run from Bilbao to San Sebastian.
For other trains in Spain, Renfe.es, Spain's official rail website, is a mess and has been described as "like Alice in Wonderland, where nothing seems to be what it really is" by Trip Advisor. Residents of Canada and USA should use Rail Europe instead to have their tickets delivered to their home address. Note that you can't book Euskotren tickets with Rail Europe. Simply turn up and get on.
Book Train Tickets in Spain with Rail Europe.
Bilbao to San Sebastian by BusThere are regular buses throughout the day from Bilbao to San Sebastian. The ones run by ALSA cost about seven euros and take just over an hour (unless you get the slow version that does more stops). The ones run by Pesanet don't list their prices but they are unlikely to be that different from those run by ALSA.
You can book most bus tickets in Spain online for only a tiny administration fee (about one euro). Just pay with a credit card and print out the e-ticket.
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Bilbao to San Sebastian by CarThe 100km journey from Bilbao to San Sebastian should take just over one hour, driving mainly on the A-8 road.
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Flights from Bilbao to San SebastianThere are no flights from Bilbao to San Sebastian.
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