The Barcelona Metro is a network of rapid transit electrified railway lines that run mostly underground in central Barcelona and into the city's suburbs. It is part of the larger public transport system of Barcelona, the capital of Catalonia, Spain, with unified fares under the Autoritat del Transport Metropolità (ATM) scheme. As of 2014, the network is operated by two separate companies: Transports Metropolitans de Barcelona (TMB) and Ferrocarrils de la Generalitat de Catalunya (FGC). It is made up of 12 lines, combining the lines owned by the two companies. Two lines, L9 and L10, are being built at present, with both lines having different sections of each opened between 2009 and 2018. They are due to be fully completed in 2026. Three lines on the network have opened as automatic train operation/driverless vehicle systems since 2009: Line 11 being converted to driverless first, and then Lines 9 and 10, opening up driverless.

The Metropolitan Transport Authority is a public consortium intended to coordinate the operation and project the expansion of the public transport system in the Barcelona metropolitan area. It is made up of the Government of Catalonia and local administrations. It has been known as ATM Àrea de Barcelona since 2003 to differentiate it from the other existing Catalan public transport authorities in the Girona, Camp de Tarragona and Lleida areas, which are also identified as ATM. As of January 2015, the ATM-managed public transport system comprises 50 different operating companies and serves 346 municipalities, accounting for a population of over 5.7 million.