El Callao was founded by Spanish colonists in 1537, just two years after Lima (1535). It soon became the main port for Spanish commerce in the Pacific. The origin of its name is unknown; both Indian (particularly Yunga, or Coastal Peruvian) and Spanish sources are credited, but it is certain that it was known by that name since 1550. Other sources point to the similarity with the Portuguese word calhau [pebble], having a similar sound.
At the height of the Viceroyalty, virtually all goods produced in Peru, Bolivia, and Argentina were carried over the Andes by mule to Callao, to be shipped to Panama, carried overland, and then transported on to Spain via Cuba.
After the Battle of Ayacucho, 9 December 1824, that sealed the independence of Peru and South America, Spain made futile attempts to retain its former colonies, such as at the Siege of Callao (1826). On 20 August 1836, during the Peru-Bolivian Confederacy, President Andrés de Santa Cruz mandated the creation of the Callao Littoral Province (Provincia Litoral del Callao), which had political autonomy in its internal affairs. During the government of President Ramón Castilla, Callao was given the name of Constitutional Province (Provincia Constitucional), on 22 April 1857; before that, Callao had the name of Littoral Province. All of the other Peruvian provinces had been given their names by law, while Callao was given it by constitutional mandate.
Callao was never part of the Lima Department nor of any other departments.
The province's first mayor was Col. Manuel Cipriano Dulanto.
By 1949, Callao was known as one of the biggest centers of coca-based products and cocaine traffic in the world.
- On 28 October 1746, a tsunami caused by the 1746 Lima–Callao earthquake destroyed the entire port of Callao.
- On 22 January 22, 1826, besieged by nationalist forces backed by Simón Bolívar, General José Ramón Rodil surrendered Callao to General
- On 2 May 1866, during the Battle of Callao, the Spanish fleet tried to reconquer independent Peru.
- Kon-Tiki left Callao, Peru, on the afternoon of April 28, 1947.
- On 19 June 1986, dozens of Sendero Luminoso terrorists tried to escape but encountered the government's naval forces on El Frontón, resulting in the so-called Peruvian prison massacres.