The use and testing of nuclear weapons caused transnational and catastrophic humanitarian and environmental consequences. Legacies of more than 2,000 nuclear detonations in the territories of 15 states persist today, with serious implications for human rights and sustainable development. There is an inadequate global policy architecture for addressing the humanitarian and environmental consequences of nuclear weapons. However, the Treaty on the Prohibition of Nuclear Weapons (TPNW), adopted by 122 states at the UN in 2017, established obligations to assist victims of nuclear weapons and testing and remediate contaminated environments. Other global policymaking bodies have also mandated action on such concerns. In this review article, introducing a Special Section on ‘Addressing the Humanitarian and Environmental Consequences of Nuclear Weapons’, we provide a global overview of the facts about past nuclear weapons activities in different countries and some of the known and potential ongoing consequences of the blast, heat and radioactive energy released by past nuclear weapons detonations. In doing so, we aim to inform the development of policy around the TPNW and the gathering of further relevant information, enabling efforts to develop global humanitarian, human rights and sustainable development policy assisting communities affected by nuclear weapons.