The genus Killickia is described to accommodate the South African endemic species formerly placed in Micromeria sect. Hesperothymus. Morphological data, as well as results from unpublished phylogenetic studies support its separation from the genera Micromeria and Clinopodium. A new species Killickia lutea Bräuchler is described and three new combinations are made. Killickia is characterised as comprising solitary- or few-flowered cymes, a campanulate to subcampanulate (obconical) calyx with similar teeth, a corolla tube with two pubescent ridges and nutlets with scattered minute hairs. A thickened marginal vein in the leaves as typical for Micromeria is absent. As currently understood all species are restricted to the Drakensberg mountains and KwaZulu-Natal Midlands in eastern South Africa. A key to the species, brief notes on anatomy and ecology are provided. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157, 575–586.