Robust morphological data are key to systematic and ecomorphological studies, but Karoo dwarf tortoises (Chersobius boulengeri) are difficult to sample due to scarcity and secretive behavior, resulting in scant published recordings of shell dimensions based on data gathered at many locations over many years. We sampled, for the first time, a single population of Karoo dwarf tortoises in 2018–2020 and report shell dimensions for 52 males, 37 females, and 5 juveniles. Male and female shells were dimorphic in size, volume, and shape, and a comparison with speckled dwarf tortoises (Chersobius signatus) suggests subtle congeneric differences in sexual dimorphism.