Purpose: Literature shows that sexual and gender minority (SGM) individuals are at higher risk of developing minority stress-related mental health problems. Recently, it has been suggested that promoting self-compassion through affirmative mental health care for SGM people can be beneficial. However, no systematic analysis has been published exploring the relationship between self-compassion and mental health indicators in SGM individuals. We aim to fill this gap by synthesizing and meta-analyzing studies that focus on the relationship between self-compassion and mental health in SGM people. Methods: After registering in PROSPERO (CRD42021254774), PubMed, PsycINFO, CENTRAL, and Web of Knowledge were systematically searched to identify studies assessing the association between self-compassion and mental health and/or minority stress indicators in SGM individuals. All screening steps and data extraction were performed independently by the two researchers. The quality of each study was assessed with the National Heart, Lung and Blood Institute tool, and meta-analysis was performed on R software. Results: Twenty-one studies were included in the meta-analysis, corresponding to a total of 6573 nonheterosexual and/or noncisgender participants. All meta-analytic models were significant: higher levels of self-compassion were associated with less depression, anxiety, psychological distress, suicidal ideation, internalized homophobia/transphobia, and stigma, and with more well-being, outness, and social support. Conclusion: This meta-analysis suggests that self-compassion is significantly associated with mental health indicators in SGM people, and this relationship is especially strong with internalized homophobia/transphobia in older SGM adults, and with suicidal ideation in younger SGM individuals. Results suggest that affirmative mental health care may benefit from promoting self-compassion.