Redwood Valley is a census-designated place in Mendocino County, California, United States. It is located 9 miles north of Ukiah, the county seat, at an elevation of 722 feet, and comprises the northern portion of the Ukiah Valley. It is about 15 miles southeast of Willits. Potter Valley is to the east and Calpella to the south. The ZIP Code is 95470, and the community is in area code 707. The population of the CDP was 1,843 at the 2020 census.