This study examined the relations among mindfulness, nonattachment, depressive symptoms, and suicide rumination in undergraduate college students (N = 552). Hypothesized pathways and mediation were tested using path analysis. As hypothesized, depressive symptoms were negatively associated with both mindfulness and nonattachment; and suicide rumination was negatively related to mindfulness and nonattachment, and positively associated with depressive symptoms. Moreover, the mindfulness–suicide rumination and nonattachment–suicide rumination associations were both in part, mediated by depressive symptoms. Implications for the improved treatment of young adults at risk for depression and suicidal behaviors are discussed.