Piru is a small unincorporated historic town located in eastern Ventura County, California, in the Santa Clara River Valley near the Santa Clara River and Highway 126, about seven miles east of Fillmore and about 13 miles west of Interstate 5. Lake Piru, in the Los Padres National Forest, is the main recreational attraction. The population was 2,063 at the 2010 census, up from 1,196 when the 2000 census was enumerated.