Avenida Roque Sáenz Peña (also known as Diagonal Norte), is a main artery in the San Nicolás quarter of Buenos Aires, Argentina. It is oriented south-east/north-west, diagonally bisecting the city blocks (manzanas) which give the city centre a checkerboard plan. It is named after President Roque Sáenz Peña, who held power from 1910 to 1914 and passed the law which established universal suffrage, secret ballot and an electoral register.
The north-west corner of Plaza de Mayo is the start of Avenida Presidente Roque Sáenz Peña (i.e. the corner of Avenida Rivadavia and San Martín street), just to the north of the city hall. It runs directly to the northwest and diagonally crosses the following streets: Bartolomé Mitre, Juan Domingo Perón and Sarmiento, and calle Florida, Maipú, Esmeralda, Suipacha and the Carabelas passage, before arriving at Plaza de la República, location of the Obelisk of Buenos Aires, where Avenida 9 de julio meets Avenida Corrientes. Still in a straight diagonal line, it crosses this intersection and continues to the next crossroads, the junction of Lavalle and Libertad in Plaza Lavalle, opposite the Courts of Justice.
Below the entire length of the avenue runs Line of the Buenos Aires Metro, which has two stations along the Diagonal (stations Catedral and 9 de julio) and a third station (Tribunales) near its western end. Line of the Buenos Aires Metro also has one station: Diagonal Norte.