Metal matrix composites (MMCs) have become integral to modern technological advancements due to their superior mechanical properties, such as enhanced tensile strength, hardness, and reduced weight. Among these, aluminum metal matrix composites (AMCs) have gained significant attention in research and industry because of their versatility and wide range of applications across aerospace, automotive, and structural sectors. Despite their advantages, challenges arise during the joining and fabrication processes. This paper provides a comprehensive review of factors influencing the mechanical and microstructural properties of AMCs when joined using the friction stir welding (FSW) process. FSW, a solid-state joining technique, has shown great potential in overcoming issues associated with traditional welding methods, such as defects and poor joint quality. Key parameters, including tool geometry, welding speed, rotational speed, and the influence of reinforcements, are explored to understand their roles in optimizing the properties of AMCs.