Friction stir welding (FSW) is increasingly utilized in aerospace for welding dissimilar Al–Mg alloys without melting, overcoming fusion welding challenges. This summary highlights FSW’s key aspects for dissimilar Al–Mg alloys and its aerospace relevance. These alloys are widely used in aerospace due to their beneficial properties, but fusion welding faces issues like brittle intermetallic compounds (IMC) and decreased mechanical properties. FSW addresses these challenges by using a rotating tool to generate frictional heat, plasticizing the material for solid-state joining without melting. This reduces IMC formation, enhancing joint strength and mechanical properties. Critical parameters like rotational speed, traverse speed, tool design, and process variables are emphasized for optimal FSW of dissimilar Al–Mg alloys. Joining these alloys is crucial in aerospace for applications such as aircraft structures, engine components, and fuel tanks. FSW offers advantages like weight reduction, improved fuel efficiency, and structural integrity enhancement. It allows welding dissimilar Al–Mg alloys with varying compositions for tailored material combinations meeting specific needs. In conclusion, FSW of dissimilar aluminum alloys is promising for aerospace, creating defect-free joints with improved mechanical properties. However, further research is needed to optimize parameters, explore tool designs, and validate long-term performance in aerospace environments.