Mission Viejo High School is a four-year comprehensive public high school located in Mission Viejo, California, United States, as part of the Saddleback Valley Unified School District. The school has served the area since 1966. Students within its attendance boundaries live in western Mission Viejo, southwest Lake Forest, Trabuco Canyon, Rancho Santa Margarita, and Laguna Hills. Its mascot is Pablo the Diablo and its colors are scarlet and gold. 230 credits are required to graduate. It is the home to one of the only agricultural farms on a high school campus in the Saddleback Valley Unified School District.

Mission Viejo is a commuter city in the Saddleback Valley in Orange County, California, United States. 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 in size. Its population as of 2020 was 93,653.