Somis is an unincorporated community in Ventura County, California. It was established in 1892 by Thomas Bard and D.T. Perkins on a portion of the Rancho Las Posas Mexican land grant. Somis is in the Las Posas Valley on the south bank of Fox Barranca, just west of Arroyo Las Posas. The name of this townsite may have been derived from “water of the scrub oak,” a Chumash placename referring to the presence of water. There was a Ranchería named Somes noted in records from 1795 and 1796.