• Microwave pyrolysis efficiently converts solid waste into hydrogen and CNMs. • Dielectric heating supports rapid and uniform thermal decomposition of waste. • Catalysts (metal, bimetallic, non-metallic) enhance CNM quality and hydrogen yield. • Microwave power, temperature, and time critically influence product formation. • Challenges include catalyst poisoning and process scale-up. The enormous amount of solid waste generated annually necessitates a transition toward circular economy strategies, especially targeting solid wastes such as waste tires, plastics, and biomass. This review explores microwave-assisted pyrolysis as a sustainable and efficient approach for converting these wastes into valuable products, specifically carbon nanomaterials (CNMs) and hydrogen gas (H 2 ). Compared to conventional pyrolysis, microwave-assisted techniques offer superior energy efficiency, faster heating rates, and higher product quality. A core focus of this review is the significant influence of catalysts and process parameters on the outcomes of microwave pyrolysis. Transition metal catalysts, particularly iron (Fe), cobalt (Co), and nickel (Ni), have demonstrated superior performance in enhancing both H 2 yield and CNMs synthesis. Bimetallic and composite catalysts exhibit enhanced microwave absorption and catalytic efficiency, making them highly suitable for this application. Moreover, critical process parameters, including microwave power, temperature, and residence time, play a pivotal role in determining product yield and quality. High microwave power and optimal temperature promote selective hydrogen generation and improve CNMs morphology, while prolonged residence time enhances gas yield. Finally, this review identifies existing knowledge gaps and outlines promising future directions for the efficient production of CNMs and hydrogen from various solid wastes using microwave-assisted pyrolysis.