Avenida da Liberdade is one of the main avenues in the city of Lisbon, Portugal, which connects Praça dos Restauradores to Praça do Marquês de Pombal. Approximately 90 m wide and 1100 m long, it has several lanes and wide sidewalks decorated with gardens and a Portuguese sidewalk. 

Avenida da Liberdade and Praça dos Restauradores have their origins in the boulevard called Passeio Público, begun in 1764 and created by the architect Reinaldo Manuel.

Initially walled, the slope underwent major changes in the 1830s and 1840s by the architect Malaquias Ferreira Leal, who introduced a new arrangement of gardens and fountains, with waterfalls and allegorical statues representing the Tagus River and the Douro River.

After much controversy, the avenue was built between 1879 and 1886, in the image of the boulevards of Paris. Its creation was a milestone in the expansion of the city to the north and quickly became a reference for the wealthier classes to locate their residences there.

Many of the original buildings on the avenue have been replaced in recent decades by office buildings and hotels.

Today the avenue still contains very interesting buildings from an artistic and architectural point of view, especially from the late 19th century and early 20th century. There are also statues of writers such as Almeida Garrett, Alexandre Herculano, António Feliciano de Castilho and others, and a Monument to the Dead of the Great War (First World War) that was inaugurated in 1931, the work of Rebelo de Andrade and Maximiano Alves, and which situated close to Parque Mayer.

Its scenic qualities, prestigious shops, hotels, theaters and historic buildings make it a tourist landmark in the city.

It is considered the 35th most expensive avenue in the world.

Avenida da Liberdade is also the main stage for the traditional parades of the city's festivities that take place on the night before the feast of Santo António de Lisboa (the night of June 12th to 13th), in which the neighborhoods of Lisbon compete with each other for the "best gait".

On June 18, 2013, Avenida da Liberdade was classified as a Public Interest Complex.