Based on institutional betrayal theory, this research examines whether students' perceptions of being dehumanized by their universities mediate the relationships between different types of interpersonal mistreatment on campus (i.e., bullying victimization, sexual harassment, ostracism) and impaired student well-being. A cross-sectional study (N = 2,318) was conducted among Belgian university students using online questionnaires. Structural equation modeling results indicated that, when considered together, all types of interpersonal mistreatment were positively associated with institutional dehumanization. In turn, students' perceptions of being dehumanized by their universities were associated with worsened well-being, including lower life satisfaction, increased depression, and more somatic symptoms. Institutional dehumanization partially mediated the relationship between interpersonal mistreatments and well-being. Theoretical contributions, future research directions, and practical implications are discussed.