The current global situation requires urgent decision-making to reverse processes of mass extinction of thousands of species. As a way of showing the importance of joint actions in this process, we aim to present the concept of One Conservation as a new proposal for the integration of sustainability, in situ and ex situ conservation for the restoration of ecosystems. According to the United Nations, we are beginning the decade of ecosystem restoration and in association with the International Union for Conservation of Nature guidelines, we can join efforts in the conservation of the planet. The survival of many species of wild animals depends on the management of populations currently maintained in ex situ conditions (under human care). To facilitate the exchange of genetic material between in situ and ex situ populations, reproductive biotechniques have become a great tool, making it possible to restore species in their natural environments. For effective conservation to occur, there must be an integrated view of the problem as a whole, and action for solutions must take place jointly by different spheres of society. Even more, conservation must be carried out by the public sector, the private sector, the third sector, and not less importantly, the agricultural sector. Therefore, One Conservation is defined as an interconnection between ex situ and in situ conservation plans, anthropic actions in the environment, and research in different areas that encompass conservation.