Constitución railway station is a large railway station in Constitución, a barrio in central Buenos Aires, Argentina. The full official name of the station is Estación Plaza Constitution reflecting the fact that the station is located opposite Constitution Square, two kilometers to the south of the Obelisco landmark. The ground floor of the station has fourteen tracks and the floor below has two tracks for the Buenos Aires Underground.

The Buenos Aires Underground, locally known as Subte, is a rapid transit system that serves the area of the city of Buenos Aires, Argentina. The first section of this network opened in 1913, making it the 13th earliest subway network in the world and the first underground railway in Latin America, the Southern Hemisphere, and the Spanish-speaking world, with the Madrid Metro opening five years later, in 1919. As of 2023, Buenos Aires is the only Argentine city with a metro system.