The global disconnect between the Sustainable Development Goals (SDGs) and the Convention on the Rights of the Child (CRC), has been described as ‘a missed opportunity’. Since devolution, the Welsh Government has actively pursued a ‘sustainable development’ and a ‘children’s rights’ agenda. However, until recently, these separate agendas also did not contribute to each other, although they culminated in two radical and innovative pieces of legislation; the Rights of Children and Young Persons (Wales) Measure (2013) and the Well-being and Future Generations (Wales) Act (2015). This article offers a case study that draws upon the SDGs and the CRC and considers how recent guidance to Welsh public bodies for implementation attempts to contribute to a more integrated approach. It suggests that successful integration requires recognition of the importance of including children in deliberative processes, using both formal mechanisms, such as local authority youth forums, pupil councils and a national youth parliament, and informal mechanisms, such as child-led research, that enable children to initiate and influence sustainable change.