High-entropy alloys (HEAs) have shown immense potential due to their unique microstructures and exceptional mechanical properties. Additive manufacturing (AM) has emerged as a powerful technique for processing HEAs in recent times, enabling unparalleled control over microstructural evolution and hence mechanical response. The current study highlights the recent advancements in microstructure design strategies for HEAs fabricated via AM, focusing on the phase stability, grain refinement and nanostructure development. The influence of processing route on tailoring heterogenous microstructures and mechanical behaviour is critically examined. Special emphasis is placed on strengthening mechanisms, ductility optimization, and the role of post-processing in enhancing performance. Finally, key challenges, opportunities and future directions are outlined to guide the rational design of AM-processed HEAs for structural applications.