The X'Trapolis 100 is a class of single deck electric multiple units (EMU) part of Alstom's Trapolis family of trains, operated in Melbourne, Victoria, Australia and Valparaíso, Chile.

The Valparaíso Metro (Metro Valparaíso, formerly Merval) is the commuter rail system serving the urban conglomeration of Gran Valparaíso, Chile. It consists of one line, 43 kilometres long, serving 20 stations, connecting the cities of Valparaíso, Viña del Mar, Quilpué, Villa Alemana, and Limache. It is administered by Metro Regional de Valparaíso S.A., a subsidiary of the Chilean state-owned train company Empresa de los Ferrocarriles del Estado (EFE).

The Valparaíso Metro began with the conversion of an interurban service on the Santiago–Valparaíso railway line in 1999, into more rapid transit-like service in 2005 – the renovated line was inaugurated on November 23, 2005 and began service the following day.

The X'Trapolis 100 was the first EMU in Melbourne to have computer-controlled traction, braking and safety systems. A continuous electrical circuit runs along the length of the train, which, when energised allows the train emergency brakes to release. The circuit will be de-energised by a number of events, such as the driver releasing a vigilance control, applying an emergency brake or passing a signal at stop. This will cause the train to apply all brakes.

Valparaiso Metro has a fleet of 35 trains; 27 single-deck multiple-car X'Trapolis 100 train sets manufactured by Alstom, France operate the service, in a blue and white livery and 8 single-deck multiple-car X'Trapolis Modular train sets manufactured by Alstom, in Barcelona.

Unlike the Melbourne version, Metro Valparaiso's trains do not have intermediate cars. They only consist of two cars with a cabin, one motor (which has the pantograph) and another trailer. They can also operate as double units, forming convoys of 4 wagons, but always smaller than the Melbourne version.

The door system is the same as in the Melbourne version. The doors are activated by pressing a button on the door and are closed by the driver or after two minutes. Each car has three passenger doors per side, which gives a total of six doors per single car and 12 per trainset. Each car has a single pantograph that delivers energy to the motor car from the catenary available throughout the network. Due to the lack of a catenary, the trains do not operate beyond the Limache station.