The site of the capital city dates from pre-Hispanic times. The early inhabitants of the area were the peaceful Quitu people, who gave their name to the city.

By the time the Spanish arrived in Ecuador in 1526, Quito was a major Inca city. Rather than allowing it to fall into the hands of the Spanish conquerors, Rumiñahui, a general of Inca ruler Atahualpa, razed the city shortly before their arrival. There are no Inca remains. The present capital was founded on top of the ruins by Spanish lieutenant Sebastián de Benalcázar on December 6, 1534. Colonists arrived, along with a host of religious orders (Franciscans, Dominicans and Augustinians, among others), and built churches, monasteries and public works, often with the labor of indigenous people. Quito grew slowly during the 17th and 18th centuries but remained a backwater in comparison to Lima.

Revolutionary fervor swept through the city in the 19th century, and Quito became the capital of the newly formed Republic of Ecuador in 1830. Population growth and building projects transformed the city over the following century, with a new astronomical observatory (the first in South America), a key rail line to Guayaquil boosting commerce, and other works. The colonial center remained the commercial heart of the city until the post-WWII years, when the city experienced (as it does now) rapid growth and expansion, fueled in large part by work-seeking immigrants arriving from all parts of Ecuador.