The Cuyama River is a 118-mile-long (190 km) river in southern San Luis Obispo County, northern Santa Barbara County, and northern Ventura County, in the U.S. state of California. It joins the Sisquoc River forming the Santa Maria River. The river's name comes from an Indian village named for the Chumash word kuyam, meaning "clam" or "freshwater mollusk".

The Sisquoc River is a westward flowing river in northeastern Santa Barbara County, California. It is a tributary of the Santa Maria River, which is formed when the Sisquoc River meets the Cuyama River at the Santa Barbara County and San Luis Obispo County border just north of Garey. The river is 57.4 miles (92.4 km) long and originates on the north slopes of Big Pine Mountain, at approximately 6,320 feet (1,930 m). Big Pine Mountain is part of the San Rafael Mountains, which are part of the Transverse Ranges.