Stevenson Ranch is an unincorporated community and census-designated place located in the Santa Clarita Valley of Los Angeles County, California. Situated in the foothills of the Santa Susana Mountains, the community lies west of Interstate 5 and the city of Santa Clarita.
The area encompasses approximately 6.4 square miles (17 km2) and was established as a master-planned community approved by the county Board of Supervisors in 1985. About 1,000 acres (4.0 km2) of the land are dedicated to open space, parks, and recreation areas. According to the 2020 census, Stevenson Ranch had a population of 20,178.