Existing unreinforced masonry (URM) buildings typically exhibit poor seismic behavior due to their age and inherent vulnerabilities, as they were generally designed for vertical loads only. Consequently, these buildings often require structural retrofitting to enhance their seismic performance. It is now widely acknowledged that the methods used for assessing the seismic performance of existing buildings and designing repair and retrofitting interventions should differ from those prescribed by technical standards for designing new structures. The design standards and safety criteria adopted for new buildings can result in “over-design,” which may lead to invasive and costly solutions when applied to existing structures, where the principle of minimum intervention should be pursued. Moreover, the implementation of some strengthening interventions into numerical models can be challenging. Due to software limitations or the assumptions inherent in the chosen modeling strategies, the numerical model is not always able to accurately assess the actual effects of the selected retrofitting solutions and reliably predict the enhanced seismic performance of structures. In this context, the paper first reviews the currently available seismic retrofitting techniques for URM buildings, classifying them into three categories based on their impact on structural response. Next, a selection of these techniques is applied to a URM archetype building to quantify their effect on structural performance and examine the implications for safety assessment according to the procedures outlined in relevant codes. Both traditional solutions and innovative techniques will be investigated. The results of this study will aim to provide recommendations to guide practitioners in selecting and designing the most appropriate repair and strengthening interventions.