Among coal mining-related wastes, coal gangue (CG) is the heterogeneous waste generated during the mineral processing or coal washing phase of coal mining. A thorough understanding of environmental concerns associated with the current model of CG utilization and potential future application is gaining paramount importance. Though previous review articles on CG have presented the environmental concerns and current utilization of CG, an appraisal on the factors affecting its mechanical properties and feasibility of CG as a potential geotechnical material has not been taken into consideration. An attempt is made here to present the different issues associated with the disposal of CG and highlight the potential benefits of its utilization. The physical, chemical, mineralogical, geotechnical, environmental (trace metal mobilization and life-cycle assessment) characteristics of CG are comprehensively evaluated to gauge its potential in promoting sustainable development. This review article also provides insights into CG's potential applications including its use as a subgrade and subbase material in pavements, landfill liner material, and filter material for hydraulic structures. The sustainability benefits attainable through CG utilization in geotechnical and geoenvironmental applications are also highlighted. © 2022 American Society of Civil Engineers.