Good policy starts with good data, which is why the work of Together for Girls (TfG) begins with nationally representative Violence Against Children Surveys (VACS), led by the Center for Disease Control and Prevention (CDC) as part of the TfG partnership. The VACS generate data on prevalence and incidence of physical, sexual, and emotional violence as well as risk and protective factors, consequences of violence, and access to services. VACS have generated data for almost 10% of the world’s youth population (aged 13–24). VACS data catalyzes and informs national action to prevent and respond to violence. With strong data to guide the way, national governments lead the development and implementation of a comprehensive multi-sector policy and programmatic response to violence against children (VAC).