Quillota is a city located in the valley of the Aconcagua River in Valparaíso Region, Chile. It is the capital and largest city of Quillota Province. It is surrounded by the communes of San Isidro, La Palma, Pocochay, and San Pedro. It is an important agricultural center, mainly because of the plantations of avocado and cherimoya trees.

The Valparaíso Region is one of Chile's 16 first order administrative divisions. With the country's second-highest population of 1,790,219 as of 2017, and fourth-smallest area of 16,396.1 km2 (6,331 sq mi), the region is Chile's second most densely populated after the Santiago Metropolitan Region to the southeast. The region also includes Chile's remote islands of the Pacific Ocean, including Rapa Nui and the Juan Fernandez Islands.