Objective: The impact of cannabis use disorder (CUD) on education functioning and GPA was examined within the context of co-occurring alcohol use disorder (AUD), major depressive disorder (MDD), and post-traumatic stress disorder (PTSD). Participants: Undergraduates (N = 210) who reported using cannabis within the past six months were recruited. Methods: Hierarchical multiple regression analyses were used to determine whether CUD symptom severity and presence of probable CUD diagnosis predicted educational impairment and current GPA, over and above other mental health conditions. Results: CUD symptom severity, but not probable CUD, significantly predicted greater educational impairment, over and above probable PTSD and MDD, which were also significant predictors. CUD symptom severity, but not probable CUD, significantly predicted lower GPA. Conclusion: In addition to other common mental health conditions, CUD may be an important area of assessment and intervention for university counseling centers to foster student academic success.