This study examines the impact of key stamping process parameters on metallic bipolar plates for Proton Exchange Membrane Fuel Cell (PEMFC) performance using computational fluid dynamics (CFD) combined with thermal and electrochemical simulations and applying the design of experiments based on the Taguchi method. An exhaustive study on this topic is not found in the literature, and this study aims to identify the most influential parameters and their interactions to optimize channel geometries for enhanced PEMFC performance within manufacturing limits. Main effects analysis revealed the BP–GDL contact length-to-pitch ratio as the most influential parameter, achieving the best performance at its higher end (0.4). The external radius showed improved performance at a lower value (0.14 mm), while pitch and channel height had smaller effects, favoring lower values (1 mm and 0.3 mm, respectively). The channel angle exhibited minimal impact but slightly improved performance at 35°. Interaction analysis highlighted a complex relationship between pitch and angle, indicating that their combined effects on current density vary with specific value combinations. A higher pitch (2.5 mm) reduced performance with lower angles, whereas a lower pitch (1 mm) improved performance with reduced angles. Finally, two new geometrical designs derived from these optimized parameter combinations enhanced fuel cell performance by 1.97% and 1.23% over the baseline, demonstrating the Taguchi method’s value in optimizing the geometrical design of metallic bipolar plates in PEMFCs. These findings contribute to advancing more efficient and practical fuel cell technologies.