This paper focuses on the application of composite materials to improve the in-plane shear strength of existing brick masonry walls. The experimental program involved the construction of walls composed of handmade solid clay brick and hydraulic lime mortar joints, a recurrent typology for historical buildings in the Mediterranean countries. The walls were tested under both unreinforced and reinforced configurations, being the latter obtained by either externally bonded textile reinforced mortar (TRM) or structural repointing with near surface mounted (NSM) rebars into the bed joints. Both TRM and NSM compounds were embedded in hydraulic lime mortar. The diagonal compression tests on retrofitted specimens considered different double-sided TRM configurations. One of them consisted in a novel asymmetric layout based on basalt TRM on one face, and NSM steel reinforcing bars on the other face. The experimental results illustrate the suitability of the proposed TRM and NSM solutions for seismic retrofit and post-earthquake repair of existing masonry buildings. The research outcomes highlight the effectiveness of the investigated systems in increasing the resistance and ductility of unreinforced brick masonry.