Objective: This study investigates the association between adverse childhood experiences (ACEs) and mental health among a sample of college students. It also explores whether health behaviors and social support may help to explain the link between ACEs and mental health. Participants: Participants were students at a large public university in the Southwest (n = 404). Methods: A survey captured ACEs, diet, exercise, smoking, binge drinking, perceived social support, depression, anxiety, and demographics. Results: Respondents with four or more ACEs had significantly higher rates of depression and anxiety than respondents with lower ACE scores. We found significant differences in social support, but not health behaviors for the two groups. Finally, social support emerged as a strong predictor of depression/anxiety and a mediator between childhood adversity and mental health outcomes. Conclusions: Our findings confirm the importance of adverse childhood experiences for college student health and indicate a need for interventions for socially isolated students.