The development of resilient cities has become a critical global issue with respect to the stimulation of sustainable economic, social, and ecological advancement. The Yangtze River Delta region, which is the most densely populated region in China, is undergoing the fastest urbanization and is achieving the highest level of economic development in the country. Thus, it is of great theoretical and practical significance to study the evolution of spatiotemporal city resilience in this region. For this study, the resilience of 41 core cities in the Yangtze River Delta in China from 2010 to 2020 was evaluated through a combination of game weighting and fuzzy matter-element analysis. Subsequently, the spatiotemporal differences in city resilience were revealed via the Dagum Gini coefficient and the Kernel density model. Further, the driving factors of city resilience were analyzed by a geographic detector model. The results revealed the following: (1) The resilience of the cities under study experienced a gradual upward trend (with Shanghai being consistently in the lead) and significant differences occurred between them. (2) The Dagum Gini coefficient indicated that the resilience of cities in the western portion of the Yangtze River Delta was quite diverse. This phenomenon was primarily due to the differences between sub-regions, for which the differences between the southeast and northwest were the most prominent. (3) The Kernel density indicated the absolute differences across the entire Delta as well as the northern sub-region, and there was a significant polarization phenomenon in the southern and western sub-regions. (4) Driving factor analysis revealed that the driving force of the income levels of residents was stronger and more stable, the driving force of economic development level was weakened, and the driving force of medical and health conditions, the degree of openness, and energy utilization efficiencies were strengthened. Overall, the driving factors of city resilience became more diversified and complex. Consequently, the Yangtze River Delta needs to improve city resilience levels in the northwest region in order to promote its balanced development. Our results suggested that more attention should be allocated to the improvement of the livelihoods of urban residents, the adjustment of energy consumption structures, and the optimization of the provision of medical resources.