Positive psychology interventions are an effective means for cultivating flourishing, addressing low levels of wellbeing, and preventing languishing. Peer-led interventions can be a particularly advantageous delivery method of positive psychology interventions, as participants tend to respond more favourably to people that they can identify with personally. Such interventions have been applied in a variety of settings and populations, but the literature on peer-led positive psychology interventions has not yet been summarised. This paper provides a narrative overview of peer-led positive psychology interventions. We reviewed relevant peer-led interventions, assessed the available evidence on their effectiveness, and highlighted promising opportunities for peer-led positive psychology interventions. We found that the majority of the studies were observational in design but showed a high level of acceptability for participants across the reviewed domains. In particular, schools, workplaces, the aged care sector, and community settings are noted as promising target domains for these interventions. However, more studies—particularly high-quality research—will be needed to comprehensively test the effectiveness of peer-led positive psychology interventions. We discuss opportunities for future research in this field.