The composition of High Entropy Alloys is quite different from the existing classical engineering alloys because in near equiatomic ratios they contain multiple principal alloying elements. Design and development of high entropy alloys is very important to overcome the shortcomings of conventionally used alloys in applications where operating conditions of temperature and loading are extreme. High entropy alloys generally find applications in compressor blades of an aerospace engine, energy, and transportation industries due to its low density and high strength. In order to enhance the application of high entropy alloys, the proper selection of a feasible welding process is very important. It has been observed that when high entropy alloys are subjected to the welding process other than the Friction Stir Welding process then it will result in reduced overall strength and lower hardness in the fusion zone and heat-affected zone. In this recent paper, the application of Friction Stir Welding for joining the high entropy alloys and also using Friction Stir Processing for improving the mechanical and microstructure properties of high entropy alloys are discussed.