Although injury is the leading cause of death for Americans aged 40 and under, curricula in U.S. Schools of Public Health rarely include training on injury prevention or control. Domestically and internationally, when the topic of injury is addressed, the focus is often on unintentional injuries. Yet intentional injuries from violence and self-harm (apart from acts of war and terrorism) and the acute and chronic health problems associated with them take a large and often hidden toll on individuals, families, and communities worldwide. Adequate education on the prevention of violence and suicide by teenagers remains missing from public health and medical training. Public health and medical practitioners are confronted by violence-related injury but are provided little formal education on youth violence or suicide, effective responses, or prevention. Adolescents' involvement in violence remains a serious public health problem. Involvement in aggression and self-harm by adolescents leaves them at immediate risk of injury and often has ongoing and negative effects on future development, involvement in community and family life, and risk of morbidity and mortality for self and others. Public health practitioners are at the nexus of health care and service provision at local, state, federal, and multinational levels, and are well suited to provide training and technical assistance on youth violence prevention across disciplines and settings. In this article, training resources, opportunities, and strategies for prevention of the high prevalence of youth violence and suicide in the U.S. are discussed and recommendations for a new public health training initiative are outlined.