Californio (historic and regional Spanish for "Californian") is a term used to identify a Spanish-speaking, mostly Roman Catholic people, or of Latin American descent, regardless of race, born in California from the first Spanish colonies established by the Portolá expedition in 1769 to the Treaty of Guadalupe Hidalgo in 1848, in which Mexico ceded California to the United States. Descendants of Californios are also sometimes referred to as Californios. The much larger population of indigenous peoples of California were not Californios because they were not native Spanish-speakers. Neither were the significant numbers of non-Spanish-speaking California-born children of resident foreigners.

The military, religious and civil components of pre-1848 Californio society were embodied in the thinly populated presidios, missions, pueblos and ranchos. Until they were secularized in the 1830s, the twenty-one Spanish Missions of California, with their thousands of more or less captive native converts, controlled the most (about 1000000 acre per Mission) and best land, had large numbers of workers, grew the most crops and had the most sheep, cattle and horses. After secularization, most of the Mission lands were divided up into new ranchos and granted to Mexican citizens (including many Californios) resident in California.

The Spanish colonial and later Mexican national governments encouraged settlers from the Northern and western provinces of Mexico, as well people from other parts of Latin America, most notably Peru and Chile, to settle in California. They encouraged new settlers to become Spanish and/or Mexican citizens, including suggested conversion to the Roman Catholic Church.