Ouigo is a French low-cost service range of both conventional and high-speed trains. The literal translation of Ouigo from French to English is "yes go"; the name is also a play on words with the English homonym "we go." It is composed of two different services: Ouigo Grande Vitesse, which is a brand of SNCF operating high-speed trains; and Ouigo Vitesse Classique, a brand under which Oslo, a subsidiary of SNCF, operates conventional speed trains.

The Société nationale des chemins de fer français is France's national state-owned railway company. Founded in 1938, it operates the country's national rail traffic along with Monaco, including the TGV, on France's high-speed rail network. Its functions include operation of railway services for passengers and freight, as well as maintenance and signalling of rail infrastructure. The railway network consists of about 35,000 km (22,000 mi) of route, of which 2,600 km (1,600 mi) are high-speed lines and 14,500 km (9,000 mi) electrified. About 14,000 trains are operated daily.