The 2030 Agenda for Sustainable Development was adopted on 25 September 2015 at the United Nations Summit on Sustainable Development. This new agenda comprises 17 agreed Sustainable Development Goals which replace the Millennium Development Goals adopted in 2000. What role will science play in realizing Agenda 2030? What are the related challenges and opportunities? The following opinion piece attempts to answer these questions. Since governments have agreed that Agenda 2030 should reflect an integrated vision of sustainable development, science cuts across virtually all 17 of the Sustainable Development Goals within this agenda. Provisions related to science are also to be found in the Declaration, in many of the targets accompanying the Sustainable Development Goals and in the Means of Implementation, including as regards national investment in science, technology and innovation, the promotion of basic science, science education and literacy, and, lastly, in the parts of Agenda 2030 on monitoring and evaluation. Science will be critical to meeting the challenge of sustainable development, as it lays the foundations for new approaches, solutions and technologies that enable us to identify, clarify and tackle local and global problems. Science provides answers that are testable and reproducible and, thus, provides the basis for informed decision making an effective impact assessments. Both in its scope of study and its applications, science spans the understanding of natural processes and the human impact thereon, the organization of social systems, the contribution of science to health and well-being and to better subsistence and livelihood strategies, enabling us to meet the overriding goal of reducing poverty.