Cyanea kauaulaensis H. Oppenheimer & Lorence, sp. nov., a new, narrowly endemic species from Maui, Hawaiian Islands is described, illustrated with field photos, and its affinities and conservation status are discussed. It is currently known from 62 mature plants and is restricted to Kaua`ula and Waikapu valleys on leeward western Maui. It differs from all other species of Cyanea by its combination of many-branched habit; glabrous, unarmed, undivided leaves; small, narrow, glabrous corollas with small calyx lobes that do not persist in fruit; and bright orange, subglobose to obovoid fruits.
Keywords: Campanulaceae; Cyanea; Hawaiian Islands; IUCN Red List; Maui; conservation.