The city of San Sebastian (Basque: Donostia) is located in the Basque Autonomous Community in the north-east of Spain. It is connected to major destinations around the world through several airports in the neighborhood.
In the vast majority of cases, flying to Bilbao Airport is the best option. A shuttle bus conveniently connects the Bilbao Airport with the Train Station of Donostia. From the train station, one can take a taxi to reach your hotel. Alternatively, bus number 45 (see timetables at city bus service d-bus) connects the train station to most central parts of the town.
Bilbao Airport (BIO): About 1 hour and 15 minutes drive from San Sebastián. A shuttle bus running every hour (or even every 30 mins in high season) connects Bilbao Airport and San Sebastián for about 17 € one way. The bus timetable is available at http://www.pesa.net (you need the connection: AEROPUERTO BILBAO ⇆ DONOSTIA-SAN SEBASTIAN). The airport is located in Loiu, a place near Bilbao.
San Sebastian Airport (EAS): About 20 minutes drive from San Sebastián. A small airport with domestic connections to Madrid and Barcelona, performed mainly by Iberia. A regular bus connects the airport and the city (timetable is available at http://www.lurraldebus.eus.) A taxi from the airport to the city center costs around 30 €. Note that the airport is located in Hondarribia.
Biarritz Airport (BIQ): About 40 minutes drive from San Sebastián and on the french side of the Basque Country. Air France flies to this airport, as well as some low-cost airlines, such as Ryanair. Bus connections are available from this airport to San Sebastián (see https://www.alsa.es).
The Adif train station “Estación del Norte” is in the center of San Sebastián, on the right side of the river Urumea. It offers connections to several Spanish cities, including Madrid and Barcelona.
There is also Metro Donostialdea, http://www.euskotren.es, popularly known as “Topo”, a narrow-gauge train connecting San Sebastián with cities along the Basque Coast, from Bilbao to Hendaye (France). The Topo is useful if you travel within France by train to Hendaye or arrive in Hendaye, for example, by taking the bus 816 from the Biarritz Airport. In such cases, look for Metro Donostialdea near the train station of Hendaye and take the Topo train; get down at the main metro station of San Sebastian (the stop is called Amara).
The San Sebastián bus station has lines to cities throughout Spain. The main company traveling here is ALSA http://www.alsa.es.
The public transportation within the city and its suburbs can be looked up on the webpage of d-bus (Donostia-bus).
The city is connected to the rest of Spain by the N-1 (Madrid-Irun highway), AP-8 (Bilbao-Irun highway), and A-15 (Pamplona-San Sebastián highway).