This study examined the mediating role of forgiveness in the relationship between unfinished business and psychological resilience among university students. A total of 434 undergraduate students (299 females, 134 males, 1 other; Mage = 22.21, SDage = 3.95) participated in the study. Participants completed a demographic information form, the Unfinished Business Scale, the Connor-Davidson Psychological Resilience Scale - Short Form, and the Heartland Forgiveness Scale (assessing self-, other-, and situational forgiveness). Data were analyzed using descriptive statistics, Pearson correlation analyses, and multiple mediation analyses with Process Model 4 employing regression-based bootstrapping techniques. The results indicated that the proposed mediation model explained 23% of the variance in psychological resilience. Self-forgiveness emerged as a significant mediator in the relationship between unfinished business and psychological resilience, whereas forgiveness of others and forgiveness of situations did not demonstrate significant mediating effects. Specifically, unfinished business was associated with lower psychological resilience through reduced self-forgiveness. These findings suggest that interventions aimed at enhancing psychological resilience among university students experiencing unfinished business may particularly benefit from fostering self-forgiveness.