Culturally related experiences are seldom considered in assessing risk for suicidal behavior among emerging adults, despite racial/ethnic differences in suicide attempts. The present study examined the impact of culturally related stressors on hopelessness, symptoms of depression, and suicidal ideation well-known predictors of suicidal behavior among emerging adults over time, and whether hopelessness would mediate the relation between culturally related stressors and both depression and ideation. An ethnically diverse sample of 143 emerging adults, ages 18 to 25, completed self-report measures of acculturative stress, perceived discrimination, and depressive symptoms at 1 time point, and self-report measures of ethnic identity, hopelessness, depressive symptoms, and suicidal ideation 2 to 3 years later. Higher baseline acculturative stress and perceived discrimination predicted hopelessness, but not symptoms of depression, when entered simultaneously into a regression analysis. However, there was an indirect relation between these culturally related stressors and depressive symptoms through hopelessness. There was also a direct relation between acculturative stress at baseline and suicidal ideation at follow-up, and hopelessness mediated this relation. However, the indirect relations between culturally related stressors and depression and suicidal ideation through hopelessness were only present at low levels of ethnic identity, but not at average or high levels of ethnic identity. Acculturative stress and perceived discrimination may thus increase vulnerability to depression and suicidal ideation to the extent that they increase hopelessness, but a strong ethnic identity may buffer against this relation. This study highlights the need for incorporating culturally related experiences in assessing risk for suicidal ideation and behavior, particularly among emerging adults from diverse backgrounds.