Eight specimens of an undescribed species of Tetramorium in the T. solidum-group were collected by pitfall trapping during an environmental impact assessment survey of the Oena Diamond Mine in the Richtersveld National Park, South Africa. The new species is most closely related to T. grandinode Santschi, 1913 but can be distinguished from this species by the distinctly different patterns of costulate sculpture on the mesosomal dorsum and petiole node, as well as the different forms of the petiole and postpetiole nodes, both of which in the new species are relatively narrower and longer and with no (petiole) or reduced (postpetiole) lateral extensions. Tetramorium nama sp. nov. is described here and a modification to the key presented by Mbanyana et al. (2018) to accommodate the additional species is provided. The potential threats to the species posed by alluvial diamond mining, livestock farming and climate change are discussed. A preliminary assessment of the conservation status of Tetramorium nama sp. nov is presented and suggests that, dependant on determination of the range of the species, it is likely to be classified as Vulnerable (VU) or Endangered (EN) under IUCN Red List criterion B1ab(iii).