Lumkuia is an extinct genus of probainognathian cynodont. It is the earliest and most basal known member of Probainognathia, with fossils being found from the Cynognathus Assemblage Zone of the Beaufort Group in the South African Karoo Basin that date back to the early Middle Triassic. Lumkuia is not as common as other cynodonts from the same locality such as Diademodon and Trirachodon. Previously, early probainognathians were only known from younger strata in South America that were deposited in the late Middle and Late Triassic. The genus has been placed in its own family, Lumkuiidae.
The postcanines are similar to the later chiniquodontids, but the secondary palate is quite short in comparison, and the genus lacks the angulation of the ventral cranial margin seen in chiniquodontids. Lumkuia can be seen as more derived than other contemporary cynodonts such as Cynognathus with the crowns of its teeth high and narrow and having inwardly curving tops. The genus was named in 2001 on the basis of the holotype specimen BP/1/2669, which can now be found at the Bernard Price Institute in Johannesburg, South Africa.