Amhara Metal Industry and Machine Technology Development Enterprise is a leading manufacturing industry in Bahir Dar, and it produces a wide range of industrial machinery and products. The main welding process used to join the products is MIG welding, which has several flaws, including low weld metal toughness, formation of spatter, the occurrence of undercut, and finally poor tensile strength and toughness. Another welding process utilized by the company is TIG welding, which employs an inert gas to create less smoke and fumes, Although this technology produces precise welds, it is a time-consuming operation and has a lower production rate. Hence there is a need of a special type of welding process which includes the properties of both the type of welding process. So the hybrid TIG-MIG welding combination was proposed. This paper presents the optimization of process parameters of EN24 mild steel material for TIG-MIG hybrid welding. The experiment was conducted on a 6 mm EN24 mild steel plate. Butt joint configuration was employed. Process parameters; MIG welding current, TIG welding current, MIG welding voltage, TIG welding voltage, and welding gun travel speed were utilized. Process parameters are optimized making use of single-level L27 orthogonal array. Mechanical properties of the weld joint are examined by means of tensile test, and hardness test. Based on the mean effect plot of GRG the optimum level setting of the test are MIG welding current of 200 A, MIG welding voltage of 15 V, TIG welding current of 200 A, TIG welding voltage of 18 V, and welding gun travel speed of 5 mm/s. ANOVA was conducted to investigate the significant process parameters. From the ANOVA, MIG welding current, and MIG welding voltage were significant factors with percentage contributions of 44.19%, and 49.20%, respectively. Five confirmation tests were conducted, and the results indicate that the mean grey relational grade of the conformation test was 0.7594, and this result falls within the 90 % confidence interval, hence the experiment is proven reliable. Finally, a comparison was made between MIG welding, TIG welding, and TIG-MIG hybrid welding processes, with the results indicating that TIG-MIG hybrid welding has the greatest hardness and tensile strength of all. Based on the findings, it is possible to conclude that the company should adopt the hybrid welding method to improve the hardness and tensile strength of the weld joint. Key words: TIG-MIG hybrid Welding, Taguchi method, Welding Processes Parameters, Grey Relational Analysis, Mechanical Properties