The Plaza del Congreso is a square located in the city of Buenos Aires, bounded by Entre Ríos Avenue and the streets Rivadavia, Hipólito Yrigoyen and Virrey Cevallos. Commonly confused as Plaza de los Dos Congresos, this confusion arises because the monument there is called De los Dos Congresos, in honor of the Assembly of the year XIII and the Congress of Tucumán.

It is part of a set of three squares in the same area, together with Plaza Lorea and Plaza Mariano Moreno. The construction of these squares was an urbanistic initiative around the celebrations of the centenary of the May Revolution, inspired by the hygienist thinking of the late nineteenth century that promoted ventilated and sunny spaces in the cities.

Located in the neighborhood of Montserrat, the history of the Plaza del Congreso begins with the purchase of a two-hectare farm by Isidro Lorea in 1782, known as Hueco del Mercado de la Piedad. Lorea donated land to the government for a plaza, which Viceroy Rafael de Sobremonte named in his honor in 1808. During the 19th century, this area included a small lagoon and several commercial and industrial establishments.

The Plaza del Congreso was projected by National Law 6,286 of 1908, which stipulated the creation of a park linking the Plaza Lorea and the new Plaza del Congreso. Among the projects presented, the one by Carlos Thays was chosen, which respected the request not to divide Plaza Lorea. The work was completed in 1910, creating a promenade that connected with the Palace of Congress, following the route of Avenida de Mayo. The original design was maintained until 1968, when it was modified to accommodate vehicular traffic.

In 1997, the three squares and their surroundings were declared a national historic site. In early 2006, a process of restoration of the square began, including the repair of sidewalks, the addition of recreational spaces and the restoration of the Monument of the Two Congresses. Currently, the monument is protected by a fence to prevent acts of vandalism. In 2017, several works to enhance the value of the Plaza del Congreso, Plaza Mariano Moreno and Plaza Lorea were completed, significantly expanding the green spaces.

Among the monuments highlighted are Rodin's El Pensador, the Mariano Moreno Monument, and the Monument of the Two Congresses. In addition, the Plaza Mariano Moreno houses the Monolith of Kilometer Zero and the Monument to José Manuel Estrada. In the Plaza del Congreso, there is also a sculpture dedicated to Alfredo Palacios, inaugurated in 2013.