Objectives: Based on acculturative family distancing theory, we examined whether familial acculturative stress interacted with hopelessness to predict suicidal ideation differentially among emerging adult immigrant versus nonimmigrant college students. Participants: We recruited 152 generationally and racially/ethnically diverse college students (42 immigrants) from 2012 to 2013. Methods: Participants completed measures of hopelessness, depressive symptoms, ethnic identity, familial acculturative stress, and suicidal ideation. Results: Immigrant status interacted with hopelessness and familial acculturative stress. Hopelessness was associated with less suicidal ideation among immigrants than among nonimmigrants at a familial acculturative stress score below the 11th percentile, but greater suicidal ideation among immigrants than among nonimmigrants at a familial acculturative stress score above the 72nd percentile. Conclusions: Familial acculturative stress may exacerbate the effect of hopelessness on suicidal ideation among immigrant college students, and should be monitored during suicide risk assessment and treatment.