Objective: To explore the relations between trauma exposure and anxiety and depression among college students, and to determine whether trait mindfulness may moderate these relations. Participants: Self-report survey data from 2,336 college sophomores were drawn from a larger university-wide study (“Spit for Science”). Methods: We constructed multiple linear regression models using past-year trauma exposure, trait mindfulness, and their multiplicative interaction to predict current anxiety and depressive symptom severity, while controlling for covariates. Results: Mindfulness was associated with lower levels of depression and anxiety symptom severity. Trauma was a significant predictor of anxiety, but not depression, and high levels of mindfulness attenuated the association between trauma exposure and higher anxiety symptom severity. Conclusions: These results have implications for the treatment and prevention of anxiety among trauma-exposed college students and provide a basis for further research into the mechanisms through which mindfulness may facilitate positive mental health.