Mission Viejo is a city located in southern Orange County, California, U.S. in the Saddleback Valley. Mission Viejo is considered one of the largest master-planned communities ever built under a single project in the United States, and is rivaled only by Highlands Ranch, Colorado, in its size. The city has a 2011 estimated population of 93,483.
Mission Viejo is suburban in nature and culture. The city is mainly residential, although there are a number of offices and businesses within its city limits. The city is known for its picturesque tree-lined neighborhoods, receiving recognition from the National Arbor Day Foundation. The city’s name is a reference to Rancho Mission Viejo, a large Spanish land grant from which the community was founded.