Objective Mixed evidence for the associations among depression, hopelessness, alcohol problems, and suicidal ideation in college students may be due to the influence of social support. Method A moderated–mediation analysis was conducted to examine relationships among suicide risk factors in 2,034 college students. Results Social support moderated the relation between depressive symptoms and hopelessness in predicting suicidal thoughts; specifically, the association between depressive symptoms and hopelessness was diminished among those students with high levels of social support. This resulted in attenuated indirect associations between depressive symptoms and suicidal ideation via hopelessness. Alcohol problems were associated with likelihood of experiencing suicidal ideation, but not severity. Conclusion Social support may be a key variable for suicide prevention among college students.