Constitución is a barrio or neighborhood of Buenos Aires, Argentina, approximately two kilometers south of the city's center.

It is centered around Constitución Station and the square of the same name.

It can be reached by subte, by bus (notably Colectivo 60) and by car, especially using avenues 9 de Julio, San Juan, and Caseros, and the 25 de Mayo toll road.

Though adjacent to the tourist-popular San Telmo neighborhood, it is seen as a dangerous barrio, though except for a few robberies the most obvious crime there is prostition by transvestites. Still, you must be careful at night there, especially if a tourist.