This paper examines progress and limitations in the transition from current dependence on carbon-based energy toward clean, renewable, and socially just energy in the Hindu Kush Himalaya and the Andes. Focusing on electricity production from sustainable hydropower, solar, and wind energy, the assessment does not cover biomass energy, although this is recognized to be an important energy source in these regions. Using meta-analysis methods, a set of 68 peer-reviewed publications was reviewed to systematically address 2 research questions: (1) Which electricity generation options in mountains can address local demands and adaptation needs while supporting broader decarbonization efforts? (2) What technical innovations, policy, and governance mechanisms can aid this transition? Considering governance, finance, individual and collective action, and science and technology dimensions of the transition challenge, recommendations for policymakers, mountain communities, and practitioners are made. These include setting up clear and effective policy measures, programs, and incentives to support energy transition plans and help mountain communities and energy practitioners to fully embrace the transition. Strong political commitment supported by international cooperation for a transition agenda centered on mountain people will enable community participation, stimulate technological innovation, and establish mechanisms to monitor and enforce social and environmental impact remediation.