<p>The investigation of dissimilar materials joining using Friction Stir Welding process has become a prominent research trend due to its growing use in aerospace, automotive, and shipbuilding industries. Over the past two decades, it has emerged as one of the most significant advancements in metal joining technology. This review brings together the key insights of research developments in the field, with an emphasis on the fundamental concepts behind Friction Stir Welding, tool design and materials, and the essential process parameters influencing joint quality. Also, the paper focuses on friction stir welding of dissimilar materials, examining the impact of preheating and water cooling on various characteristics like hardness, tensile strength, and fatigue behavior. This literature review critically examines recent advancements in dissimilar welding of aluminum–magnesium alloys, offering essential design recommendations for future studies. It presents a comprehensive overview of existing knowledge and points out important areas that need more investigation.</p> Graphical Abstract <p></p>