This work presents the design, simulation, and fabrication of a custom prosthetic foot intended for transtibial amputees. The project integrates anatomical measurements, CAD modeling, material selection, and finite element analysis (FEA) to optimize structural performance under both static and dynamic conditions. A polylactic acid (PLA) model was manufactured using FDM 3D printing with a 60% infill density, balancing mechanical resistance and low production cost. The elastic behavior of the damping system was represented by a compression spring, whose stiffness was experimentally determined and integrated into the simulations. Static analysis validated the structural stability under a 980 N load, with maximum von Mises stress below the material’s yield strength. A mesh convergence study ensured numerical consistency, while dynamic analysis simulated the prosthesis performance throughout the gait cycle, evaluating progressive loading on the rearfoot, midfoot, and forefoot. Moderate displacements and distributed stresses confirmed that the design preserves its integrity under realistic conditions. The final prototype demonstrates functional characteristics such as energy return, adaptability to terrain, and shock absorption, offering an affordable alternative for users with active lifestyles. This work highlights the relevance of digital simulation and iterative design for improving access to biomechanically effective and context-appropriate prosthetic solutions.