<p>Aluminum/stainless steel bilayer sheets have been found to have increasing applications in the automotive and food industries due to their corrosion resistance and high strength-to-weight ratio. The microstructure and mechanical properties of rolled A11050/SS304 bilayers were experimentally examined in this study. The bilayer composite was first prepared using the roll bonding method. Regarding the low strength of Al, roll bonding of the Al/SS composite bilayer could be a proper approach to enhance the strength of the specimens. The mechanical properties such as yield and ultimate strength, elongation, and stress–strain diagram were determined by tensile and microhardness methods, while the microstructure of the samples was evaluated by optical and scanning electron microscopes at various reduction ratios and thicknesses. Regarding different parameters of the roll bonding process, the Box–Benken experiment design was adopted in this research. The Al/SS bilayer was prepared using three reduction ratios and three Al and SS sheet thicknesses. According to the experimental results based on the design of experiments (DOE), the yield strength and elongation of the 17 bilayer samples showed a 2.5-fold and 40% increase compared to the initial aluminum sheets. The increase in the yield strength of the bilayer can be assigned to the activation of the diffusion mechanism. An increment in the reduction ratio of the thickness of the interface showed a decline, while the bilayer yield and ultimate strength exhibited an increase. In samples 5 and 7 with the same layer thickness, a change in the reduction ratio from 45 to 75% decremented the thickness of the interface from 9 to 7&#xa0;µm while the ultimate strength of the bilayer rose by 14%.</p>