Two new species of Cryptocephalus Geoffroy, 1762 are described from the Baja California peninsula, Mexico: C. drewi sp. nov., and C. incognitus sp. nov., with illustrations of the male genitalia presented for the former. Specimens previously reported as C. sanguinicollis nigerrimus Crotch, 1874 from the Baja California peninsula were determined to represent C. drewi, while specimens previously reported as C. vapidus White, 1968 were identified as C. californicus Clavareau, 1913. As a result, C. sanguinicollis nigerrimus and C. vapidus are removed from the list of chrysomelid species believed to occur in the Baja California peninsula. A non-type male specimen of C. californicus is described, and differences between the male and female are provided. Color habitus photographs and information on distribution are provided for all three species.