In light of rising academic stress and an increase in diagnosed mental illnesses among adolescents and young adults, this article offers the first comprehensive analysis of relationships between perceived competition and depression/anxiety among college students. Analyses were conducted by using clinically validated instruments for depression and anxiety and a diverse, national sample of 40,350 undergraduates from 70 institutions. Multivariate logistic regressions reveal that high levels of perceived competition in one's classes are associated with increased risks of depression and anxiety, especially among queer, first-generation, Black, and Latino/a students. Discrimination and peer support moderate these relationships, suggesting avenues for future research and educational interventions.