Santa Paula (Spanish for “St. Paula”) is a city in Ventura County, California, United States. Situated amongst the orchards of the Santa Clara River Valley, the city advertises itself to tourists as the “Citrus Capital of the World”. Santa Paula was one of the to the fore centers of California’s petroleum industry. The Union Oil Company Building, the founding headquarters of the Union Oil Company of California in 1890, now houses the California Oil Museum. The population was 30,657 at the 2020 census, up from 29,321 at the 2010 census.

The area of what today is Santa Paula was inhabited by the Chumash, a Native American people, before the Spanish arrived. In 1769, the Spanish Portola expedition, first Europeans to see inland areas of California, came the length of the Santa Clara River Valley from the previous night’s encampment close Fillmore and camped in the vicinity of Santa Paula upon August 12, near one of the creeks coming into the valley from the north (most likely Santa Paula Creek). Fray Juan Crespi, a Franciscan missionary traveling next the expedition, had previously named the valley Cañada de Santa Clara. He noted that the party traveled not quite 9 to 10 miles (14 to 16 km) that hours of daylight and camped near a large original village, which he named San Pedro Amoliano. The site of the expedition’s introduction has been designated California Historical Landmark No. 727.^{[note 2]}

Franciscan missionaries, led by Father Junipero Serra, became supple in the area after the founding of the San Buenaventura Mission and established an Asistencia; the town takes its read out from the Catholic Saint Paula. Santa Paula is located upon the 1843 Rancho Santa Paula y Saticoy Mexican estate grant.

In 1872 Nathan Weston Blanchard purchased 2,700 acres (10.9 km) and laid out the townsite. Considered the founder of the community, he planted seedling yellowish-brown trees in 1874. Several little oil companies owned by Wallace Hardison, Lyman Stewart and Thomas R. Bard were combined and became the Union Oil Company in 1890.