The increased amount of terrorist activities directed against U.S. facilities led to an evaluation of the survivability of masonry structures to blast loadings. Un-reinforced masonry (URM) walls have a low resistance against out-of-plane blast loading due to their low flexural capacity and their brittle mode of failure. Therefore, failures of URM walls were identified as one of the major causes of material damage and loss of human life due to blast loads. This led to an urgent need in developing effective retrofitting techniques instead of impractical conventional approaches to upgrade masonry members to resist blast loads. An alternative method is using Fiber Reinforced Polymer (FRP) composites on the surfaces of the walls to resist high flexural stresses. However, this is a new approach to blast resistant design and there is little available test data to use as a basis for design of wall upgrades. Two series of walls, reflecting different slenderness ratios and strengthened with FRP composite materials were included in this research study by varying charge weights and standoff distances. FRP composites in the form of rods and laminates were used as strengthening materials. The walls were supported from the top and bottom and subjected to blasts from mid-height. The tests caused a well-distributed range of damage levels; from no damage to complete failure and the shear capacity controlled the blast behavior of the strengthened walls. Furthermore, the analytical analysis showed that the single degree of freedom (SDOF) approach can be used to predict the behavior of masonry walls strengthened with FRP. Conclusions and design guidelines relating deformation limits to threat and damage levels are provided with recommended future research needs.