Reversing biodiversity loss is a global imperative that requires setting aside sufficient space for species. In South Africa, an estimated area of 20 million ha is under wildlife ranching, a form of private land enterprise that adopts wildlife-based land uses for commercial gain. This land has potential to contribute towards biodiversity conservation, but the extent to which this occurs has not been evaluated. Using structured questionnaires of 226 wildlife ranchers, we assessed how the sector contributes towards the conservation of ungulates and elephants (hereafter herbivores). Overall, 40 herbivore species were present across the sample, where individual ranches had a mean of 15.0 (±4.8) species, 1.9 (±1.5) threatened species, and 3.6 (±3.1) extralimital species per property. In comparison to 54 state PAs, wildlife ranches had significantly higher species richness, more threatened species but
more extralimital species when property/reserve size was controlled for. Ranches conducting trophy hunting had similar species richness and numbers of extralimital species per ha, but fewer threatened species when compared to ranches conducting ecotourism. We estimate that 4.66–7.25 million herbivores occur on ranches nationally, representing one of the few examples on earth where indigenous mammal populations are thriving and demonstrating how sustainable use can lead to rewilding. We discuss the potential negative impacts of widespread game fencing on landscape fragmentation and gene flow, as well as how the widespread occurrence of extralimital species may lead to hybridisation, biotic homogenisation, and changes to vegetation dynamics. Despite these challenges, commercial wildlife ranching offers a viable option for conserving large mammalian herbivore biodiversity.