Rancho Calleguas was a 9,998-acre (40.46 km2) Mexican land grant in present-day Ventura County, California given in 1837 by Governor Juan Alvarado to José Pedro Ruiz.[1]
The grant was south of Rancho Las Posas, east of Rancho El Rio de Santa Clara o la Colonia, north of the Rancho Guadalasca, and west of Rancho El Conejo. It encompassed the Santa Rosa Valley and present-day Camarillo.[2]