The Santa Rosa Valley is a small valley and rural unincorporated community in Ventura County, Southern California.The valley is about 5mi long (east to west) and 2mi wide (north to south).The community is sometimes considered to an outlying neighborhood of Camarillo, although not within its territorial limits.It is bordered on the south by the western Simi Hills and Wildwood Regional Park, and on the north by Las Posas Hills. The valley is drained principally by the Arroyo Santa Rosa, a tributary of Calleguas Creek which flows into the Pacific Ocean at Mugu Lagoon.
