July 9 Avenue (Spanish: Avenida 9 de Julio) is a major thoroughfare in the city centre of Buenos Aires, Argentina.

The avenue runs around 3 kilometres (1.9 mi) to the west of the Río de la Plata waterfront, from the Retiro district in the north to Constitución station in the south.

Through the centre of the avenue runs one of the city's Metrobus (Bus rapid transit) corridors, which stretches 3 kilometres (1.9 mi) and was inaugurated in July 2013.

The idea of constructing July 9 Avenue (La Avenida 9 de Julio) was proposed during the time of Mayor Francisco Seeber (1889–1890).

The Municipality of the city of Buenos Aires started the acquisition of all the properties located particular track with an investment of 50,000,000 of the currency of that time (peso moneda nacional).

[4] The matter generated a political and financial crisis of large proportions, which were also aggravated by the outbreak of the Great War[6] and the proximity of the first democratic elections that were to occur with the resignation of Mayor Anchorena and with the closing of the Municipal Counsel in 1915.

The idea to construct the July 9 Avenue was maintained in the plan of 1925 where it was integrated into the North and South diagonals (proposed in 1919), forming at the ends two central monuments.

Notably, lines B, C, and D share a station underneath the Obelisk, which is the focal point of the subway system and features a retail concourse which also serves as an underpass.

The Metrobus 9 de Julio is 3 kilometres (1.9 mi) long with 13 stations and runs down the avenue, taking roughly the same route as Line C of the Buenos Aires Underground.