Temnothorax allardycei (Mann) (Hymenoptera: Formicidae) is a rarely encountered ant known only from the Bahamas and South Florida. I found a total of only 24 site records of T. allardycei, six in the Bahamas and 22 in South Florida. Temnothorax allardycei nests in plant cavities, notably in dead vines and dead stems of sawgrass, Cladium jamaicense (Cranz). All records of T. allardycei for which I have habitat data came from relatively intact natural areas, a pattern that suggests that this species is native to both the Bahamas and South Florida.