Commuter rail, also called suburban rail, is a passenger rail transport service that primarily operates between a city center, and the middle to outer suburbs beyond 15 km (10 miles) and commuter towns or other locations that draw large numbers of commuters—people who travel on a daily basis. Trains operate following a schedule, at speeds varying from 50 to 200 km/h (30 to 125 mph). Distance charges or zone pricing may be used.

Non-English names include Treno suburbano in Italian, Cercanías in Spanish, Nahverkehrszug in German (and in most larger cities S-Bahns though these trains also often include city centre metro-like sections where lines have merged and services become more frequent, and stations are closer together to better distribute passengers into the city core),Train de banlieue in French, Příměstský vlak in Czech and Elektrichka in Russian. The development of commuter rail services has become popular today, with the increased public awareness of congestion, dependence on fossil fuels, and other environmental issues, as well as the rising costs of owning, operating and parking automobiles.