Santa Clarita (/ˌsæntə kləˈriːtə/) is the third-largest city in Los Angeles County, and the 23rd largest in the state of California. As of the 2010 census it had a population of 176,320, and in 2018 the population was estimated to be 210,089. The city has gained much of this rapid population increase by annexing numerous unincorporated areas. It is located about 30 miles (48 km) northwest of downtown Los Angeles, and occupies most of the Santa Clarita Valley. It is a notable example of a U.S. edge city or boomburb.
Santa Clarita was incorporated in December 1987 as the union of four unincorporated communities, Canyon Country, Newhall, Saugus, and Valencia, most of which are situated within the boundaries of the former Rancho San Francisco, a historic land grant. The four communities retain separate identities, and residents commonly refer to one of them when asked where they are from. Santa Clarita is bounded on the west by the Golden State Freeway (I-5). The Antelope Valley Freeway (SR-14) runs northeast-southwest through an irregular east border, and Newhall Pass is the city's southernmost point.
Six Flags Magic Mountain amusement park and Stevenson Ranch are both commonly associated with Santa Clarita. But each is located west of Interstate 5, and thus neither is within the Santa Clarita city limits.