Dudleya crassifolia is described as new. It belongs to a complex of taxa within subgenus Hasseanthus that have a white (occasionally pale yellow) corolla with a conspicuous, “musky-sweet” odor. It differs from related species of this complex in having a thicker petiole, a leaf blade that is only slightly wider than the petiole, and conspicuous dried leaf bases persisting on the caudex. This species is very rare, currently known only from a single population of scattered individuals (total area of coverage less than one hectare), on sandstone bluffs at Colonet Mesa of north coastal Baja California, Mexico.