Since the late 1990s, scholars have studied how forgiveness—forgiveness of others, forgiveness of oneself, and divine forgiveness—enhances the well-being of both victims and perpetrators of wrongdoing. In fact, numerous lines of research have shown forgiveness to be related to physical and psychological well-being as well as relational and spiritual well-being. In the current chapter, we explore and critique four established theories (i.e., stress-and-coping, process, interdependence, and evolutionary theories) and three burgeoning theories (i.e., relational spirituality, virtue, and exposure theories) that organize portions of the literature on forgiveness and well-being. We articulate the formerly unarticulated exposure theory of forgiveness, and we adduce data and reasons that support it. We conclude that the existing empirical research on forgiveness and well-being is not captured by a single theory but rather best conceptualized according to several theories. Thus, we aim to summarize critical elements of each theory as they relate to investigations of the association between forgiveness and well-being.