La Défense station is a station of the Transilien suburban rail lines, RER commuter rail network, Paris Métro, as well as a stop of the Île-de-France tram network. In the future, Paris Metro Line 15 of Grand Paris Express will pass through here, making it a huge railway hub. It is underneath the Grande Arche building in La Défense, the business district just west of Paris. The station is the western terminus of Métro Line 1 and connects the RER A line to the Métro Line 1 station La Défense–Grande Arche since 1992, the Line 2 tramway since 1994 and SNCF (Transilien) train station. It is also attached to a major shopping centre. There are over 25 million entries and exits each year. A temporary special SNCF service began in April 1959 to serve the newly-built Centre of New Industries and Technologies (CNIT); the RER entered service on 19 January 1970.

Transilien is the brand name given to the commuter rail network serving Île-de-France, the region surrounding and including the city of Paris. The network consists of nine lines: H, J, K, L, N, P, R, U, and V each operated by SNCF, the state-owned French railway company. The lines begin and end in major Parisian stations, except for lines U and V which connect major stations outside the Paris city borders. Unlike the RER network, the Transilien trains do not cross through the Paris city centre.