Textile Reinforced Mortar (TRM) is an external reinforcement technique that involves embedding high-strength fiber fabrics—such as carbon, glass, steel, or basalt—within an inorganic cementitious or lime mortar matrix. This reinforcement strategy has proven to be highly effective in enhancing the structural response of masonry structures due to its compatibility with the substrate. This paper presents an experimental study on the seismic behavior of an unreinforced masonry (URM) wall with arch openings retroffited with TRM. For this purpose, one full-scale URM wall with arch openings was tested under constant axial load and in-plane cyclic lateral loading. Subsequently, the damaged wall was retrofitted on both sides with a basalt grid embedded in a lime-based organic matrix (BTRM). This BTRM layer was anchored to the reinforced concrete foundation at all four sides of the base of the piers using stainless steel helical bars. The retrofitted wall was then tested under the same loading protocol as the undamaged wall. The results indicated that the BTRM system improved the lateral capacity of the URM wall by 32%. Additionally, the BTRM reinforcement modified the cracking pattern, creating new cracking regions at the top of the piers in addition to those observed previously in the URM-damaged wall. Finally, a preliminary comparison was conducted between the experimental results and the analytical provisions for TRM-strengthened systems.