Agriculture and industrial wastes (AIWs) have attracted much attention because of their huge environmental, economic, and social impacts. AIWs have been considered a crucial link of a closed-loop for the fabrication of nanomaterials and composites wherein they replace traditional resources with sustainable waste in waste management. In this context, the proper disposal of AIWs is required. This review aims to investigate the technical feasibility of using innovative AIW resources and various strategies for the fabrication of nanomaterials for improving energy applications. First, the utilization of AIWs is classified comprehensively. Second, key technologies to produce nanomaterials are summarized. In addition, this review discusses the potential applications of the fabricated nanomaterials in energy storage and energy conversion.