Differential settlement of foundations is one of the key factors affecting the dynamic behavior of reinforced concrete structures, which can cause significant changes in seismic response and force distribution within frames. In this study, the effect of asymmetric foundation settlement on the dynamic response of reinforced concrete frames retrofitted with steel bracing is investigated. For this purpose, a multi-story reinforced concrete frame was modeled using numerical simulation software, and its behavior under various seismic excitations with different magnitudes of differential settlement was analyzed. The main novelty of this research lies in the simultaneous assessment of the effects of non-uniform settlement and the influence of steel braces on improving the seismic performance of frames. In this study, dynamic response metrics including inter-story drift, base shear, and the distribution of bracing forces were evaluated. The results indicate that steel braces can significantly reduce inter-story drifts and enhance the overall stability of frames against non-uniform settlements. Moreover, the effect of differential settlement on retrofitted frames is less pronounced compared to unbraced frames, and the force distribution within the frames becomes more uniform. The findings of this study can assist structural engineers in the optimal design of seismic retrofitting systems for reinforced concrete frames and in predicting structural behavior under non-uniform foundation settlement. The results also emphasize the importance of considering foundation settlement analysis in the seismic design and retrofitting of frames, and the proposed approach can serve as a comprehensive framework for evaluating the effects of differential settlement in reinforced concrete structures.