In the present study, a total of 12 experiments were carried out in order to evaluate the effect of prior in-plane damage on the out-of-plane response of structurally and thermally retrofitted masonry wallettes, simulating in a that way the behavior of upgraded masonry infills in reinforced concrete or steel frame structures under seismic loading. The specimens were retrofitted with textile-reinforced mortar (TRM), which in some cases was combined with expanded polystyrene as thermal insulation material. Testing comprised in-plane diagonal compression and out-of-plane bending on walls with or without prior in-plane damage. Numerical simulations were also performed using fiber modeling, and they were found in good agreement with test results. In-plane loaded walls with TRM only or TRM/insulation retrofitting outperformed significantly their non-retrofitted counterparts. Out-of-plane loaded walls with combined TRM/thermal insulation performed much better or at least as good as their TRM-only retrofitted counterparts, for the case with or without prior in-plane damage, respectively.