Abstract: As one of the regions with the most vibrant economy and the greatest development potential in China, conducting in-depth research on the decoupling relationship between carbon emissions, economic growth, and energy consumption and related driving factors in the Yangtze River Delta (YRD) will not only promote the region′s low-carbon transformation, but also provide crucial support for the whole country to achieve the goals of carbon peaking and carbon neutrality. This article uses the Tapio decoupling model to analyze the relationships between energy consumption, economic growth, and carbon emissions in the YRD from 2000 to 2021. Based on the Logarithmic Mean Divisia Index (LMDI) decomposition method, policy factors are introduced on the basis of traditional decomposition to distinguish the roles of the government and market forces in the low-carbon transformation, and to explore the driving factors of carbon emissions in the YRD and their influence degrees. The results show that: (1) Carbon emissions in the YRD exhibit varying degrees of decoupling in relation to economic growth and energy consumption. Among them, Shanghai shows a relatively strong decoupling state, while the other provinces show growth-link or weak decoupling states at different periods. (2) The economic development effect is the main factor driving the growth of carbon emissions, with a contribution rate of 255.13%. The fiscal emission reduction effect is the key factor restraining the growth of carbon emissions, with a contribution rate of −201.58%. The industrial structure, population, energy structure, and carbon intensity effects also play an important role in emission reduction. (3) There are significant spatiotemporal differences in the impact of various driving factors on carbon emissions in the YRD. The research indicates that carbon emissions in the YRD are gradually decoupling from economic growth and energy consumption, with the economic development effect and fiscal emission reduction effect being the key drivers influencing carbon emissions.