Surveys for beetles and plant-associated insects on San Clemente Island off southern California conducted by the California Beetle Project and the Santa Barbara Botanic Garden found four specimens of an unknown bark beetle species. Based on morphology, the beetle was identified as a Carphobius Blackman species. Given the uncharacteristic scale-like setae, generic placement was confirmed in the context of a molecular phylogeny using partial sequences of COI and 28S genes. Carphobius was sister to Chaetophloeus LeConte (Chaetophloeini) which calls into question its current tribal placement in Polygraphini. Carphobius caterinoi Cognato and Smith, new species is described and compared to the three previously known Carphobius species and similar genera. Carphobius is reviewed and a key to species and images are included. Potential host use by C. caterinoi is discussed.