Prodoxus cinereus is a moth of the family Prodoxidae. It is found from Los Angeles in the United States south to the border with Mexico. The habitat consists of coastal chaparral and montane dry shrubby grassland. The wingspan is 9–15 mm. The forewings are uniformly pale to medium brown. The hindwings are usually lighter and sparsely scaled. The larvae feed on Yucca whipplei. They feed primarily in the basal portion of the inflorescence stalk.