Rail transport in Spain operates on four rail gauges and services are operated by a variety of private and public operators. Total railway length in 2020 was 15,489 km (9,953 km electrified). The Spanish high-speed rail network is the longest HSR network in Europe with 3,973 km (2,464 mi) and the second longest in the world, after China's. 

Most railways are operated by Renfe; metre and narrow-gauge lines are operated by the Renfe Cercanias AM division. Local publicly owned operators include Euskotren in the Basque Country, FGC in Catalonia and Serveis Ferroviaris de Mallorca in the Balearic Islands. Private railway operators include Ouigo and Iryo. 

It is proposed and planned to build or convert more lines to standard gauge, including some dual gauging of broad-gauge lines, especially where these lines link to France, including platforms to be raised.

Spain is a member of the International Union of Railways (UIC)