A meta-analysis of the efficacy of forgiveness interventions in older adults was conducted. International databases (Medline, PsycINFO, Scopus, Web of Science) were searched for studies published from 1990 to 2020 that attempted to promote forgiveness in older adults. Most intervention studies are group treatments targeted towards community-dwelling older adults. Participants in these studies are mainly women. The intervention objectives and contents vary widely and often criteria are not well-defined. Participants that received forgiveness interventions reported significantly higher levels of forgiveness than participants that did not receive treatment. Additionally, forgiveness interventions resulted in more changes in depression, stress and anger than no intervention conditions. Forgiveness treatment also enhances positive states (satisfaction with life, subjective happiness, and psychological wellbeing). The reported effects are moderate. The specific treatment model (e.g., Enright’s, Worthington’s) and format (e.g., group-based interventions and individually delivered programs) do not differentially predict better outcomes. In conclusion, future intervention studies should include more male participants and utilize a broader range of follow-up periods. Caution must be exercised because of the limited number of studies developed to date; researchers must be cautious when generalizing the results.