Given the ongoing low-carbon energy transition in China, the social, economic, and environmental consequences of this transition cannot be overlooked. Achieving common prosperity is a key component of China's agenda, so it is important to consider the potential nexus between common prosperity and the low-carbon energy transition. Therefore, this study first offers a new comprehensive measure of common prosperity. Furthermore, we examine the impact of the low-carbon energy transition on common prosperity by applying the system-generalized method of moments (SYS-GMM) approach. The key conclusions reached regarding the impact of the low-carbon energy transition on common prosperity are: (1) the degree of common prosperity has continued to increase between 2006 and 2019; (2) the low-carbon energy transition significantly promotes common prosperity; (3) the low-carbon energy transition indirectly promotes common prosperity by expanding gross fixed capital formation, improving labor productivity, and promoting industrial structure upgrading; and (4) the low-carbon energy transition has a significantly stronger impact on common prosperity in provinces with higher levels of low-carbon energy transition and common prosperity. Finally, we suggest several policy implications for promoting low-carbon energy transition and common prosperity.