Escondido is a city located in San Diego County's North County region, 30 miles (48 km) northeast of Downtown San Diego, California. The city occupies a shallow valley ringed by rocky hills. Incorporated in 1888, it is one of the oldest cities in San Diego County. The city had a population of 143,911 in the 2010 census. The city is known as Eskondiid in Diegueño.

"Escondido" is a Spanish word meaning "hidden". One source says the name originally referred to agua escondida or hidden water; another says it meant "hidden treasure".