National Route 9 (in Spanish, Ruta Nacional 9) is a major road in Argentina, which runs from the center-east to the northwest of the country, crossing the provinces of Buenos Aires, Santa Fe, Córdoba, Santiago del Estero, Tucumán, Salta and Jujuy.

It starts on Avenida General Paz, which marks the border between the Autonomous City of Buenos Aires and the surrounding province of the same name, and ends at the Horacio Guzmán International Bridge, on the La Quiaca River, traversing 1,967 km (1,222 mi).

Between the cities of San Nicolás de los Arroyos and Rosario (distant about 65 km (40 mi) from each other), the road is named Teniente General Juan José Valle.

The route originated as the "Camino Real del Perú" (Royal Road of Peru), used since colonial times to travel from Buenos Aires, through Córdoba, Santiago del Estero, San Miguel de Tucumán, Salta, San Salvador de Jujuy, and Potosí, continuing to Peru.

The section between Buenos Aires and the south of what it is today Cordoba Province, was shared with the "Camino Real del Oeste" (Royal Road of the West) which branched towards San Luis, Mendoza and Santiago (Chile).

The first train from Buenos Aires arrived in the town of La Quiaca in Argentina's northern border with Bolivia on 30 December 1907.

[3] After the change of layout in 1979, the route was fully paved except for a short piece north of Humahuaca, in Jujuy Province, which was an improved road.

[7] The section passing through Greater Buenos Aires to the Port of Campana access road is part of "Acceso Norte" (a 120 km-length road that runs from Avenida General Paz (Buenos Aires city border) to Route 9, with branches to Tigre and Pilar through National Route 8).

[10] Based on this plan, by the end of the forties work was started in what is known today as "Acceso Norte" (North Access) to Buenos Aires, reaching the town of Garín in 1959.

[18] In Greater Buenos Aires, before the completion of the Accesso Norte, Route 9 ran through the present streets Boulogne Sur Mer, Presidente Sarmiento and Constituyentes Ave. in Tigre Partido.

This 15 km (9 mi) section from Don Torcuato and the border between Benavídez and Garín left national jurisdiction by the aforementioned decree.

After construction of the San Nicolás de los Arroyos - Rosario highway southeast of said railway line at the end of the 1970s, this road changed to provincial control by the aforementioned decree.