Santa Margarita (Spanish for "St. Margaret") is a unincorporated community located in San Luis Obispo County, California.

For statistical purposes, the United States Census Bureau has defined Santa Margarita as a census-designated place (CDP).

[4] Santa Margarita Valley, with its year-round running streams and abundant acorns, was a meeting place for northern Chumash and southern Salinan around 6500 BCE.

Junipero Serra founded the Mission San Luis Obispo de Tolosa, he realized that an assistancia (sub-mission) was needed.

In 1841, following Mexico's 1822 independence and 1830s mission secularization, Joaquin Estrada became the owner of the Rancho Santa Margarita.

A "Grand Auction" was held to sell lots for the new town of Santa Margarita along the El Camino Real.

The town offered a motor inn, hotel, six gas stations, garages, pool halls, restaurants, fraternal organizations, taverns and a baseball team.

The War Department took land from local farmers to build a reservoir on the Salinas River which created Santa Margarita Lake to provide water for Camp San Luis.

[5][6] Located in the foothills of the Santa Lucia Mountains, it is one of the most rural communities in San Luis Obispo County.

Santa Margarita Lake, a major water source for San Luis Obispo, is located several miles southeast of the town on the headwaters of the Salinas River.