<p>This paper presents a numerical–experimental study of microstructure evolution during cold rolling of AA1050 aluminum. For the first time, a dislocation density–based constitutive model used to simulate microstructural evolution during the cold rolling of commercially pure aluminum. The model was implemented within the ABAQUS/Explicit environment via a VUMAT subroutine to directly couple strain hardening behavior with dislocation density evolution and grain refinement mechanisms under varying thickness reductions. Cold rolling reductions of 10%, 20%, 30%, 40%, and 80% were simulated, and the resulting fields of dislocation density, equivalent plastic strain, grain size, and stress were analyzed. The results show that increasing thickness reduction intensifies plastic deformation and produces pronounced grain refinement, especially near the surface and edges, trending toward more homogeneous refinement at higher reductions. Dislocation density exhibits a rapid initial rise followed by stabilization, with the highest stabilized values obtained at 80% reduction. Experimental validation using X-ray diffraction line profile analysis for the 20% and 40% reductions demonstrates excellent agreement with simulation predictions, with discrepancies below 2%. The calibrated implementation provides a reliable framework for predicting microstructure–thickness relationships and serves as an effective tool for designing reduction schedules to achieve desired microstructural states and improved mechanical performance. Moreover, the techno-economic assessment shows that selecting Al1050 for lithium-ion components and numerical analysis of cold rolling process generated a 10-year net present value (NPV) gain of approximately USD 2.2–2.5 million compared with conventionally processed Al1060 and Al3003.</p>