Previous research documents that street-involved youth experience rates of trauma and posttraumatic stress disorder (PTSD) that are significantly higher than their housed counterparts. Trauma and PTSD are of particular concern for homeless youth as they can negatively affect youths’ ability to function adaptively and to transition off the streets. This mixed-methods study investigates the intricacies of trauma experienced by homeless youth across three U.S. cities. Qualitative interviews were conducted with a sample of 145 homeless youth in Los Angeles (n = 50), Denver (n = 50), and Austin (n = 45) to explore youths’ perspectives on the definition of trauma and the contexts associated with victimization. Quantitative standardized assessments investigated youths’ trauma experiences before and after becoming homeless. Trauma screening identified high rates of trauma incidents (78%), with 28% of participants meeting criteria for PTSD. Participants reported various traumatic experiences that occurred before leaving home and while on the streets, and high rates of polyvictimization. Qualitative themes describe particular people and places most vulnerable on the streets. Implications for services to prevent and treat trauma among homeless youth are discussed.