<p>To minimize the environmental carbon footprint by augmenting the fuel efficiency through the utilization of lightweight structural applications in aerospace, marine, and automobile industries by employing magnesium alloys owing to their exceptional strength-to-weight ratio and encouraging mechanical properties. Simultaneously, in the drive toward sustainable and energy-efficient manufacturing practices aligned with the principles of Industry 4.0, microwave hybrid heating has emerged as a promising, eco-friendly joining technique for metals, alloys, ceramics, and polymers. However, the potentials of microwave hybrid heating in joining magnesium alloys largely remain untapped and underexplored. Therefore, this study investigates the novel application of microwave hybrid heating to join AZ31B magnesium alloy, presenting a viable and sustainable alternative to conventional joining techniques. As magnesium alloy is a challenging material to be processed, the analytical modeling of the process was performed and the process parameters were gauged; subsequently, the predicted values were utilized for performing the experimental investigation. The joints fabricated were physically characterized through scanning electron microscopy, energy-dispersive spectroscopy, and x-ray diffraction, revealing comprehensive microstructural and compositional insights and, subsequently, mechanically characterized. Subsequently, the findings open new avenues for the widespread adoption of microwave hybrid heating in advanced lightweight engineering applications, reinforcing its potential as a clean, efficient, and forward-looking joining technique for next-generation manufacturing systems in the context of Industry 4.0.</p>