Poaching is the most significant contemporary threat to the world’s wild rhinos. The ability to address it will play a critical role in twenty-first century rhino conservation success and will depend on understanding and tackling poaching drivers and methods. Reflecting on the history of humans exploiting rhinos reveals that the concept of poaching is socially constructed, highlighting contested views over the rights to benefit from rhinos. In recent history there were two distinct global poaching waves: the first, starting in the 1970s, swept across most of Africa and parts of Asia until it was contained in the mid-1990s; the second surged in the early twenty-first century and peaked during 2015 but persists at threatening levels. The factors driving these waves, and the responses to them, have evolved over time, influenced by shifting socio-political conditions and technological developments. Increasing sophistication of poaching methods and levels of enabling corruption were key features of the second wave. Whereas some countries have managed to contain poaching through a combination of strict enforcement accompanied by harnessing local community support, others continue to struggle and have had to resort to measures such as dehorning to reduce the economic incentive to poach. Rhino poaching has had seriously negative consequences for conservation, having driven two Asian species to the brink of extinction and with several subspecies already extinct in both Africa and Asia. The loss of large contiguous populations has created added risks of inbreeding, and poaching pressure renders the cost of protecting residual fragmented populations prohibitively high for all but the most well-funded conservation agencies and landowners. The future of rhino conservation will depend in no small part on the ability to maintain sustainable sources of funding for comprehensive anti-poaching measures, which will continue to be necessary in both African and Asian contexts, especially if the consumer demand for rhino horn persists at current high prices.