The seismic resilience of reinforced concrete (RC) moment frames subjected to earthquake sequences has become a critical consideration in performance-based design, particularly for structures equipped with energy dissipation systems. The concept extends beyond life safety, emphasizing the ability to restore functionality after seismic events. Despite the favorable performance of buckling-restrained braces (BRBs) in dissipating energy, the combined effects of mainshock–aftershock sequences, building height, bay number, and hazard level on resilience have not been comprehensively investigated. This study quantitatively evaluates the influence of mainshock–aftershock sequences on the resilience of RC moment frames strengthened with BRBs under varying hazard levels and structural configurations. Three groups of two-dimensional RC frames with 5, 10, and 15 stories and two bay configurations of 3 and 5 bays were designed per high seismic requirements and modeled in OpenSees. The BRBs were designed according to Chapter 10 of the Iranian National Building Code and connected using pinned connections. Nonlinear dynamic time-history analyses were performed using recorded real earthquake sequences. Spectral acceleration at the fundamental period was selected as the intensity measure, while maximum inter-story drift ratio was adopted as the engineering demand parameter. Damage was quantified based on four performance levels, and fragility curves were developed to estimate damage probabilities and evaluate resilience degradation under Design Basis Earthquake (DBE) and Maximum Considered Earthquake (MCE) levels. Results indicate that increasing height and bay number significantly increases damage and reduces resilience due to greater lateral flexibility, larger drifts, and concentration of permanent deformations in lower and middle stories. The mainshock accounts for over eighty percent of total damage, whereas the aftershock has limited influence unless the structure remains in the nonlinear range. Resilience decreases markedly as hazard level increases from DBE to MCE, with the most severe reductions in taller and five-bay frames, showing approximately forty percent reduction in resilience index under MCE compared to DBE. Earthquake intensity, height, and bay number are three key parameters influencing resilience. Taller and five-bay frames exhibit the highest vulnerability. The proposed fragility-based framework provides useful insights for improving seismic design and post-earthquake evaluation of RC buildings.