The purpose of this study is to apply topology optimization to the design of a protective underbody panel for armored combat vehicles subjected to improvised explosive devices (IEDs). The increased use of IEDs by terrorist organizations over the last two decades has led to the death of thousands of soldiers and imposed critical damage to vehicles. There is interest in developing a protective panel that minimizes deflection and mass. The goal of this study is to design a lightweight, modular, and affordable panel, which provides increased protection to the vehicle occupants. Topology optimization may be used to create unique structures through a subtractive formulation. As additive manufacturing capabilities improve, topology optimization enables the design of efficient structures that are difficult to manufacture using traditional methods. Eight topology optimization studies were conducted and produced unique structural designs that were compared to established designs. The deflection, strain energy, and stress of optimized models from were compared to a hollow structural section (HSS) of equivalent mass and height. Results indicated the performance of optimized models were dependent on the topology optimization design goal. The methodology presented may be used in the future for projects which aim to minimize mass and maximize stiffness.