The recent experimental results for slender reinforced concrete beams with a thin steel fiber reinforced concrete (SFRC) jacket have demonstrated their feasibility in enhancing the performance in terms of serviceability and ultimate limit states and strongly suggested the need for a comprehensive analysis to show the effect of important parameters. Within this context, the bond between reinforced concrete (RC) beams and SFRC jacket is an essential parameter to avoid any slippage failure before the beam achieves its shear capacity. The behavior of the bonded element is affected by slip at the interface between the old and new concrete. However, it is common in design to ignore slip and consider the bonded element monolithic. The values of slip and shear stress relation of the strengthened element are reviewed in this paper. In addition, an analytical procedure for predicting the distribution of slip along the interface between the initial beam and the new layer of concrete is presented. The research paper aims to develop a detailed three-dimensional (3D) finite element (FE) model for evaluating the structural performance of RC beams strengthened with SFRC jackets taking into account the effect of the bond between the beam and the jacket. It also aims to investigate the effect of significant parameters on the response of strengthened RC beams in shear. These parameters are as follows: jacket compressive strength (30, 60, and 85 MPa), fiber volume fraction (0.5, 1.0, 1.5, and 3.0%), jacket thickness (30, 40, 50, and 60 mm), and spacing between shear connectors (100, 200, and 500 mm). The proposed model’s results were compared to those of previous experimental research. The analysis result shows good agreement with the correlating experimental measurement. The parametric study results proved that increasing the volume fraction of fiber, jacket thickness, and compressive strength of the jacket increases ductility and shear capacity. Increasing the spacing between shear connectors has no noticeable effect on shear capacity but prevents debonding. Finally, reference equations were made to study the behavior of RC beams strengthened with SFRC jackets, taking into account the effect of the bond between the beam and the jacket.