Rancho Santa Paula y Saticoy was a 17,773-acre (71.92 km2) Mexican land grant in the Santa Clara River Valley, in present-day Ventura County, California, and granted in 1843 by Governor Manuel Micheltorena to Manuel Jimeno Casarin. The rancho lands include the eponymous communities of Saticoy and Santa Paula along the Santa Clara River.
Micheltorena granted four leagues to Casarin. Manual Jimeno Casarin served as Alta California Secretary of State under Governor Alvarado and Governor Micheltorena, was a senior member of the State Assembly, and occasionally acting governor. He was married to María de las Angustias the daughter of José de la Guerra y Noriega. Casarin, who lived in Monterey, also owned Rancho Salsipuedes in Santa Cruz County and Rancho Jimeno in Yolo County. Unlike many land grants holders, Casarin was not required to show any use or development of the land and apparently he did not use the land, either for agriculture or ranching. He died in 1853 during a visit to Mexico.
Levi Parsons, Eugene Casserly, J. B. Crocket, David Mahoney and others, purchased the rancho from Casarin in 1852.
With the cession of California to the United States following the Mexican-American War, the 1848 Treaty of Guadalupe Hidalgo provided that the land grants would be honored. As required by the Land Act of 1851, a claim for Rancho Santa Paula y Saticoy was filed with the Public Land Commission in 1853, and the grant was patented to John P. Davidson in 1872.