Investing in the mental health of children and adolescents is crucial for enhancing their ability to learn, work, build meaningful connections, and positively contribute to their communities. Despite its importance, mental health remains a neglected area of data, research and evidence generation, with profound implications for individual and societal wellbeing. This proposal outlines three workstreams to drive action, aligning with UNICEF’s Mental Health Acceleration Initiative and the broader UNICEF strategic plan: \- Workstream 1 accelerates Child and Adolescent Mental Health (CAMH) data and measurement, equipping countries with timely, high-quality data by advancing contextually appropriate, reliable, and validated tools like Measuring Mental Health among Adolescents and Young people at the Population level (MMAPP), supporting data generation, collation, and use to guide informed action on child and adolescent mental health. Notably, this also includes the establishment of a multi-stakeholder engagement platform through a global Technical Advisory Group (TAG). \- Workstream 2 establishes an accountability mechanism to monitor global CAMH policy commitments, driving policy progress through increased government ambition and implementation. \- Workstream 3 empowers data-driven decision-making, builds capacity among stakeholders, including communities (specifically, youth with lived experience), and governments to foster sustainable data ecosystems.