The high plateau of southern Africa is considered to be either uplifting due to mantle-driven dynamic topography, or to have been stable since Mesozoic rifting. To address this debate, we determined rock uplift in South Africa from the long-term incision rate of the Sundays River, near Port Elizabeth, and from an uplifted marine terrace near Durban. We dated the terraces with cosmogenic 26Al and 10Be, using both isochron and simple burial dating methods. We find that the Sundays River has incised at 16.1 ± 1.3 m/m.y. for the past ∼4 m.y., and the marine terrace yields a rock uplift rate of 9.4 ± 2.2 m/m.y. These results are inconsistent with rapid Neogene uplift.