Stenogyne kauaulaensis K. R. Wood & H. Oppenheimer (Lamiaceae), a narrow endemic from Kaua‘ula, West Maui, Hawai‘i, U.S.A., is described and illustrated. The new species differs from other known species of Stenogyne Bentham by its combination of flowers raised on a common peduncle, broadly campanulate calyx with large foliaceous teeth, strongly falcate corolla, and exserted stamens. Known from approximately 15 naturally occurring individuals, S. kauaulaensis easily falls into the Critically Endangered IUCN Red List category and is successfully cultivated for conservation.