The concept to leave no one behind (LNOB) is at the core of the 2030 Agenda for Sustainable Development. Paragraph 4 of the World Leaders’ Declaration adopted in September 2015 states: As we embark on this great collective journey, we pledge that no one will be left behind. Recognising that the dignity of the human person is fundamental, we wish to see the Goals and Targets met for all nations and peoples and for all segments of society. And we will endeavour to reach the furthest behind first (United Nations, 2015). The LNOB concept encompasses individuals, groups, and countries. It underscores that no one should be left behind and highlights the need to achieve sustainable development for all nations, peoples, and segments of society. More importantly, the resolution insists that priority must be given to the most deprived. The commitment of the UN member states to leave no one behind implies that they should take explicit measures to (i) end extreme poverty in all its forms and allow the left behind to catch up with those who have made progress; (ii) reduce the inequalities and vulnerabilities that undermine a person’s ability to escape poverty; and (iii) end group-based discrimination that leads to unequal outcomes for the marginalised.