This study examined multiple types of forgiveness as predictors of mortality and potential psychosocial, spiritual, and health mechanisms of the effects of forgiveness on longevity. Data from a nationally representative sample of United States adults ages 66 and older assessed forgiveness, health, religiousness/spirituality, and socio-demographics (N = 1,232). God's unconditional forgiveness and conditional forgiveness of others initially emerged as statistically significant predictors of mortality risk. However, only conditional forgiveness of others remained a significant predictor of mortality after controlling for religious, socio-demographic, and health behavior variables. Mediators of the association between conditional forgiveness of others and mortality were examined, and a statistically significant indirect effect was identified involving physical health. These findings suggest that conditional forgiveness of others is associated with risk for all-cause mortality, and that the mortality risk of conditional forgiveness may be conferred by its influences on physical health.