Microwave-assisted casting (MAC) is an advanced material processing technique that offers a faster, more energy-efficient alternative to traditional casting methods. By utilizing volumetric microwave heating, MAC enables uniform temperature distribution, refined microstructures, and reduced defects in cast components. This chapter describes the principles, benefits, and diverse applications of MAC across various material types, including metals, ceramics, composites, and glass. It delves into key processing parameters and highlights recent case studies that demonstrate the effectiveness of this technique. The discussion also covers the integration of MAC with emerging technologies such as artificial intelligence and the Internet of Things, reflecting its alignment with the goals of smart manufacturing. While challenges such as high equipment costs and limitations in scaling up remain, the potential of MAC in critical industries—especially biomedical, automotive, and aerospace—positions it as a forward-looking and sustainable solution for enhancing material performance and manufacturing efficiency.