A large proportion of the world's extinctions have occurred in Australia, and threatened species lists continue to grow, notwithstanding government and philanthropic efforts. Most losses have been on private land, so relying on national parks and reserves is not enough to reverse trends and meet Australia's responsibilities. This paper proposes a model that could increase abundance and distribution of Australia's biodiversity, while providing financial incentives to private landholders to do so. It addresses the question, can landholder management of wildlife, and a form of private ownership, remedy shortfalls in government funding for biodiversity conservation and the resulting consequences of vast biodiversity losses? Landholders currently invest in propagating introduced livestock species, but they are prevented by current regulations from investing in a similar manner in threatened Australian native species. Market-based incentives could increase the distribution and abundance of species on private land and help protect the habitat of other biodiversity. The enabling changes would be contentious to some people but are consistent with the International Union for the Conservation of Nature's Sustainable Use policy. Different versions of wildlife privatisation have been successfully applied internationally: there is urgency for Australia to draw on these experiences and develop its own model to encourage and support wildlife on private freehold land. The model proposed in this paper focuses on: identifying locally overabundant populations or captive-bred populations as sources of supply finding landholders and philanthropists who would like to have custodianship of species; enabling entrepreneurs to respond to demand and bringing the two together where there is scope for a market-based sharing economy. Encouraging wildlife custodianship on private freehold land would be mutually beneficial, as it would not only result in an increase in biodiversity, but the economic value of wildlife could provide an income to landholders as well as enhancing Australia's conservation system.