Introduction, Part 1: Child and Youth Participation in Policy, 1. Partnering for child participation: reflections from a policy maker and a professor, 2. Informing Policy Dialogue: The Youth as Researchers Programme, 3. ‘The Children's Soap Box': Evaluating active citizenship through creative engagement, 4. ‘Are they going to do anything with this info?’: Implementing Children’s Perspectives on play and recreation policies, 5. Visible, valued and included: Prioritising youth participation in policy-making for the Irish LGBTI+ National Youth Strategy, Part 2: Child and Youth Participation in Practice, 6. Amplifying Seldom Heard Voices, 7. Children and adolescents’ participation in information-sharing and healthcare decision-making, 8. Young Peoples Experiences of Youth Participation in a Mental Health Organisation, 9. A Multi-faceted Approach to Embedding Rights Based Participatory Practice in Child Protection, Welfare and Family Support Services, 10. Art Makes You: Co-production with young people at the National Gallery of Ireland, Part 3: Child and Youth Participation in Research, 11. Locating the (adult) researcher in participatory research with children, 12. Children’s Research Advisory Groups: moving from adult-research agendas to co-creation with children, 13. Addressing race in participatory research with children and young people: Art-based methods, silence and ‘voice’, 14. Reflections from Young Research Collaborators: From Consultative Research to Child-led Dissemination, 15. The process and impact of involving children in the HBSC Ireland study, Conclusion.