This topic guide summarises some of the most rigorous available evidence on the key debates and challenges of disability inclusion in development and humanitarian response. Disability does not necessary imply limited wellbeing and poverty. Yet there is growing evidence that the estimated one billion people with disabilities face attitudinal, physical and institutional barriers that result in multi-dimensional poverty, exclusion and marginalisation. Disability inclusion could increase earnings, tax revenues, and individual and societal wellbeing. It need not be costly or complicated. Inclusive approaches are more cost-effective than piecemeal disability interventions.