Friction Stir Welding (FSW) has emerged as an effective method for joining composite materials, revolutionizing the field of composite welding. This chapter provides an in-depth exploration of FSW’s potential applications, advantages over conventional methods, and the associated challenges. By comparing FSW to existing welding techniques, current chapter demonstrate how it overcomes issues like porosity, distortion, and poor mechanical properties. Drawing from relevant literature, we delve into case studies of FSW-welded composite materials, investigating the weld joint quality and resulting material properties. The discussion extends to the identification of metal matrix composites that can be effectively joined using this innovative method, shedding light on its versatility. However, limitations are also considered to provide a comprehensive perspective. This chapter serves as a valuable resource for researchers, engineers, and practitioners in the field of materials science and engineering, offering insights into the promising future of FSW in the realm of composite material welding.