Blythe is a city in eastern Riverside County, California, United States. It is in the Palo Verde Valley of the Lower Colorado River Valley region, an agricultural area and part of the Colorado Desert along the Colorado River, approximately 224 miles (360 km) east of Los Angeles and 150 miles (240 km) west of Phoenix. Blythe was named after Thomas Henry Blythe, a San Francisco financier, who established primary water rights to the Colorado River in the region in 1877. The city was incorporated on July 21, 1916. The population was 18,317 at the 2020 census.