Redwood Valley (formerly, Basil) is a census-designated place in Mendocino County, California. It is located southwest of Potter Valley, at an elevation of 722 feet (220 m). It comprises the northern portion of the Ukiah Valley. It is about 8 mi (13 km) north of Ukiah and 12 mi (19 km) south of Willits.  Potter Valley is to the east and Calpella to the south. The ZIP Code is 95470. The community is inside area code 707. The population was 1,729 at the 2010 census.