Culicoides truuskae Labuschagne and Meiswinkel sp. n. is described and illustrated in both sexes from material collected in South Africa and Namibia. It is restricted to the xeric western margin of the subcontinent, occurring in Fynbos, Nama-Karoo and Succulent Karoo ecoregions in South Africa and Desert and Savanna ecoregions in Namibia experiencing < 600 mm of rainfall annually. Culicoides truuskae sp. n. is part of the Afrotropical ‘plain-wing’ Culicoides in which the wing lacks a distinguishing pattern of light and dark spots; the diagnostic dark smudge that traverses wing cell r3 may result in C. truuskae sp. n. being misidentified as the sympatric but phyletically unrelated Culicoides herero (Enderlein) – (of the Similis group, subgenus Oecacta Poey). Additionally, this study is the first description of the male of C. herero. C. truuskae sp. n. and Culicoides coarctatus Clastrier and Wirth share similar characters in the male genitalia, although the two species are separable on wing pattern and female flagellum sensilla coeloconica (SCo) distribution. The breeding habitat and adult female blood-feeding preferences of C. truuskae sp. n. are not known. A maximum likelihood phylogenetic tree, using mitochondrial cytochrome c oxidase I (COI) sequence data, is provided to further clarify the relationship between C. truuskae sp. n., C. coarctatus and C. herero. Extensive light trap data, collected over 30 years, are used to map the distribution ranges of C. truuskae sp. n., C. coarctatus and C. herero in Southern Africa. Keywords: Culicoides, taxonomy, description new species, DNA barcoding, map.