This paper discusses the results of an experimental campaign on Composite-Reinforce Mortar (CRM) and Fabric-Reinforced Cementitious Matrix (FRCM) jacketing for the retrofit of stone masonry structures. Two double-leaf natural stone masonry piers were built with the same materials and geometry, including portions of adjoining spandrels above and below. Then CRM was applied to both faces of one of the specimens, using a Natural Hydraulic-Lime (NHL) mortar, Glass-Fiber-Reinforced Polymer (GFRP) meshes, and helicoidal steel connectors. The other pier, instead, was retrofitted with FRCM on both sides, combining a glass-fiber-reinforced cementitious mortar, bidirectional PBO textiles, and PBO connectors. Both specimens were subjected to the same vertical overburden load and to a quasi-static cyclic shear-compression test in double-curvature conditions. The lateral loading protocol included initial cycles in force control, followed by cycles of increasing amplitude in displacement control up to failure of the piers. In both cases, the lateral strength increased by a factor of about 1.35 to 1.40 compared to that expected for an unstrengthened pier. Different collapse mechanisms were triggered by the two retrofit systems, with flexure dominating the CRM specimen and shear controlling the FRCM one. The displacement capacity was enhanced by factors of about 2.5 in flexure and 3.0 in shear, compared to typical values for unstrengthened piers.