Energy system models are widely used to explore, analyse and plan energy futures and sustainable transitions. These models, typically developed in high-income countries, have more recently been applied in low- and middle-income countries (LMICs). As a result, the role that models play in informing decisions in such contexts lacks adequate exploration. Drawing on 35 qualitative interviews with energy system modellers and policymakers, this research examines the experiences of developing and using energy system models that support decision-making in LMICs. The findings suggest that many conventional modelling approaches do not account for the political economy influences and developmental challenges specific to LMICs, with implications for modelling processes and outcomes. The interviews highlighted the need to understand the roles played by diverse stakeholders in shaping modelling processes, as well as the communication, interpretation and use of energy models. This indicates that, particularly in modelling projects which bring in external modellers, a good understanding of the country context is essential to design appropriate model scenarios and for their interpretation in policymaking. Finally, more in-country capacity is needed to foster local ownership of modelling projects.