San Marcos is a suburb of San Diego in the North County section of San Diego County, California. As of the 2010 census, the city had a total population of 83,781. Outside the San Diego region, it is best known as the home of California State University, San Marcos. The city is bordered by Escondido to the east, Encinitas to the Southwest, Carlsbad to the west, and Vista to the northwest.