Santander Airport (SDR) is about 5 km from the city centre, served by Ryanair and a handful of other carriers from various European cities. The bus into town takes around 20 minutes.
By train, Santander has two stations. The RENFE mainline station connects to Madrid (about 4.5 hours by the Alvia service) and other Spanish cities. The FEVE narrow-gauge station next door is the western terminus of the scenic coastal route along the Cantabrian shore toward Bilbao and Oviedo — one of the most enjoyable train journeys in northern Spain.
Brittany Ferries runs a twice-weekly service from Plymouth in England to Santander, making this an excellent starting point for a road trip through Iberia. The crossing takes around 24 hours.