A new look at children from the world's richest countries offers a mixed picture of their health, skills and happiness. For far too many, issues such as poverty, exclusion and pollution threaten their mental well-being, physical health and opportunities to develop skills. Even countries with good social, economic and environmental conditions are a long way from meeting the targets set in the 2030 Agenda for Sustainable Development. Focused and accelerated action is needed if these goals are to be met. The evidence from 41 Organisation for Economic Co-operation and Development (OECD) and European Union (EU) countries tells its own story: from children's chances of survival, growth and protection, to whether they are learning and feel listened to, to whether their parents have the support and resources to give their children the best chance for a healthy, happy childhood. This report reveals children's experiences against the backdrop of their country's policies and social, educational, economic and environmental contexts. [This report was written with contributions from Dominic Richardson, Céline Little, and David Anthony.]