The development of laboratory work on friction stir welding (FSW) and friction stir spot welding (FSSW) FSW of dissimilar materials should provide a good insight into their possible industrial applications; and therefore, enhance their industrial development. Many applications in various industries, especially in the manufacturing sector, have led to the development of processes, such as FSW and FSSW for similar and dissimilar materials. Aluminium and copper have different properties including melting temperatures, which make the two materials difficult to join. Choosing suitable parameters, such as rotation speed, welding speed, and tool plunge depth and dwell time is important when fabricating sound FSWelds and FSSWelds. This chapter presents the current state of FSW and FSSW of aluminium and copper. An overview of the research conducted in the field of FSW and FSSW between aluminium and copper is summarized in terms of the microstructural evolution and the mechanical properties. The quality of the fabricated welds, spot welds and explanations of various properties of the welds by various researchers is presented and summarized. This could provide an insight into the current state of the two processes; and it could also lead to the optimization of the techniques by conducting more research in the field of FSW and FSSW Al/Cu. Furthermore, future scope on the usage of the two techniques is addressed.