Purpose: The aim of the study was to examine Long-Term Impacts of Glacier Retreat on Downstream Water Availability in Ethiopia. Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: The study revealed that as glaciers continue to shrink due to climate change, the hydrological systems in mountainous regions of Ethiopia, such as the Simien Mountains and Bale Mountains, face disruptions in water supply, affecting both local communities and downstream users. The reduction in glacial meltwater contributes to decreased streamflow, altered river regimes, and increased variability in water availability, exacerbating water stress in a country already prone to droughts and water scarcity. Moreover, glacier retreat affects ecosystems, biodiversity, and livelihoods dependent on freshwater resources, further amplifying socio-economic vulnerabilities in the region. Unique Contribution to Theory, Practice and Policy: Climate Change Theory, Hydrological Cycle Theory & Systems Theory may be used to anchor future studies on Long-Term Impacts of Glacier Retreat on Downstream Water Availability in Ethiopia. Implement cutting-edge technologies for real-time monitoring of glacier melt and downstream water flow. Use satellite imagery, remote sensing, and IoT sensors to gather data that can inform water management practices in real time. Develop and enforce policies that ensure sustainable water use and prioritize the maintenance of water quality and ecosystem health. This includes setting limits on water withdrawals based on sustainability criteria and enhancing the legal frameworks protecting water rights.