Objectives <p>The present study examined a conceptual model regarding the longitudinal impact of peer support on the mental health of individuals with mental disorders. Specifically, it tested whether greater peer support would be longitudinally associated with higher levels of self-compassion and lower levels of self-stigma, leading to reduced psychological distress, more positive perceptions of recovery, and greater life satisfaction.</p> Method <p>Participants were 235 individuals with mental disorders recruited from four non-governmental organizations providing mental health services in Hong Kong. They completed questionnaire measures of peer support at baseline (Time 1; T1) and measures of self-compassion, self-stigma, psychological distress, perceptions of recovery, and life satisfaction 1&#xa0;year later (Time 2; T2). The interrelations of these variables were investigated using path analyses and bootstrap analyses.</p> Results <p>Path analyses revealed that greater peer support at T1 was associated with higher levels of self-compassion and lower levels of self-stigma, which, in turn, were linked to reduced psychological distress, more positive perceptions of recovery, and greater life satisfaction at T2. Bootstrap analyses further showed that peer support had indirect effects on psychological distress, perceptions of recovery, and life satisfaction through self-compassion and self-stigma.</p> Conclusions <p>This study demonstrates the beneficial effects of peer support in enhancing self-compassion, reducing self-stigma, and promoting mental health outcomes among individuals with mental disorders. Given the psychological benefits of peer support, mental health service providers should make concerted efforts to promote peer support for their service users.</p> Preregistration <p>This study is not preregistered.</p>