This paper presents the results of an experimental program, where a total of eight retrofitted walls were subjected to blast loading, simulated by shock waves using the University of Ottawa’s shock tube. Four different external retrofit options were considered and their behavior in terms of failure mode, stiffness, and strength were documented. Nonlinear single-degree-of-freedom (SDOF) modeling was performed using material models developed specifically for each retrofit. In general, good agreement was found between the predicted level of damage and calculated displacement using the model and the measured behavior. The study shows that a significant increase in stiffness and strength can be achieved.