Beautiful cities are a vital pillar of the Beautiful China vision. The policy document issued by the CPC Central Committee and the State Council on advancing Beautiful China calls for creating an inclusive and participatory social environment to support this national goal. In response, IPE—under the technical guidance of the Chinese Research Academy of Environmental Sciences and with the support of the Energy Foundation—developed the Beautiful City Synergy Index and launched the corresponding Beautiful City Synergy Platform to enable multi-stakeholder participation in beautiful city development. In this inaugural evaluation of 100 cities, Ningbo, Shenzhen, and Beijing ranked at the top. Other cities in the top ten included Guangzhou, Chengdu, Weihai, Fuzhou, Kunming, Yichang, and Xiamen. Among the leading performers, eastern coastal cities such as Ningbo, Guangzhou, and Weihai demonstrated strong overall performance, while Fuzhou and Xiamen excelled in environmental quality. Megacities like Beijing and Shenzhen distinguished themselves through high-quality development. In the southwest, Chengdu and Kunming advanced climate action by promoting coal-to-electricity transitions and expanding non-fossil energy use. Yichang, located in central China, stood out for its achievements in ecological enhancement.