Fiber-reinforced polymer (FRP) composites have significantly advanced construction technology by imparting superior properties such as high strength, durability, and corrosion resistance. Their application in concrete structures, particularly circular columns, has been especially notable. The bond integrity between the FRP composite and the concrete substrate is crucial for ensuring good performance and longevity of these composite structures. Debonding, defined as the separation of FRP from the concrete substrate, poses a substantial risk to structural integrity if it occurs. The guided waves’ technique is a promising method for detecting such defects. Among guided wave techniques, nonlinear guided waves have demonstrated significant efficiency for detecting and locating defects. In this research, we utilized a 3D finite element (FE) simulation approach to accurately predict the interaction of guided waves with debonding. Additionally, we developed a technique for the detection and localization of debonding. Various damage case scenarios have been considered to ensure the applicability of the proposed method in diverse situations. The findings demonstrate a good efficacy in utilizing guided waves to detect and locate minor bond defects within the cylindrical FRP-retrofitted specimens. The research also used advanced signal processing and analysis techniques to isolation the guided wave components for precise damage detection and damage localization.