A numerical validation study was conducted to simulate the capacity of a reinforced concrete (RC) frame with masonry infill wall (MIW) erected with concrete masonry units (CMU) and strengthened with textile reinforced mortar (TRM). To accomplish this, the finite element method (FEM) software ABAQUS was utilized to generate a three-dimensional (3D) FE model of the one-bay one-story TRM retrofitted specimen with 2:3 scale that was subjected to quasi-static in-plane (IP) loads previously at Wellington Institute of Technology. To identify the nonlinear response of the frame, MIW, and the TRM, an accurate numerical model was developed utilizing the appropriate constitutive models. Furthermore, a parametric study was conducted to determine the significance of the full-bond scenario between the RC frame MIW and the TRM considering: (1) opening in the MIW (2) the location of TRM and (3) the number of layers of TRM on the specimen. The numerical model was successful in accurately reproducing the IP capacity of the retrofitted MIW frames in terms of load-carrying capacity, distortion capacity, and cracking patterns. It can be observed that the specimen with two layers of TRM on both sides of the infill wall exhibit the maximum lateral load carrying capacity and maximum deflection resisting characteristics while the other retrofitted specimens controlled the deflection to some extent and significantly enhancing the load carrying capacities of the masonry system.