Both substance abuse and suicidal behavior are global public health concerns. Much of the progress made in addressing problematic substance use and suicidal ideation and behavior stems from the notion of alleviating pathological factors. Positive psychological characteristics, such as forgiveness, have received much less attention from empirical investigators. We review the extant literature pertaining to the value and role of forgiveness as an effective resource for clinicians when treating individuals struggling with substance abuse and suicidal behavior. We discuss relevant theory and research (i.e., definitions, processes, and linkages) regarding similarities in models of forgiveness, substance abuse, and suicidal behavior and conclude with an overview of various means of using the process of forgiveness as a positive psychotherapy; whether through stand-alone forgiveness interventions, infusion with Twelve-Step Facilitation Therapy, or application through acceptance-based treatment modalities. In sum, forgiveness may be an important factor in the facilitation of change in the difficult often existangst-derived struggles (i.e., emotionally and philosophically driven psychological distress) inherent to substance abuse and suicidal behavior.