Electron Beam Welding (EBW) is an important welding process in the present scenario. It is applied to various fields, including the fabrication of difficult-to-weld materials in the engineering, aerospace, and automobile industries. It can weld similar and dissimilar material with fine Heat-affected zones and produces high-strength joints. The joining of dissimilar materials becomes very easy through the EBW route. The EBW welded samples achieved a high depth-to-width ratio & focused accurately on the area to be welded. Therefore, it minimizes the area of the heat-affected zone (HAZ). In this work, the study focused on optimizing the process parameters of EBW welding parameters like current, voltage, welding speed for strength, and hardness of weld bead. The materials selected were mild steel and EN8. A Taguchi technique-based experiment has been used to find the data. Then, welding parameters are optimized to get optimum strength, hardness on the weld bead, and hardness on the heat-affected zone of the welded joint. The Optimized tensile strength was 600MPa, at Voltage = 50KV, Beam Current = 4 mA, and welding speed = 75 mm/min. The weld bead hardness was 146.4 HV, at Voltage = 50KV, Beam Current = 4 mA, and welding speed = 75 mm/min at optimized conditions. The Optimized hardness on HAZ is 163.23 HV on EN-8 & 160.43 HV on Mild steel at Voltage = 45KV, Beam Current = 4 mA, and welding speed = 50 mm/min.