This study investigates how ESG (environmental, social, and governance) performance influences the corporate value of publicly listed sports companies in China, with a focus on the mediating role of intangible assets and the moderating effect of the policy environment. Analyzing panel data from 41 A-share sports firms over 2009–2023 using a two-way fixed-effects model, the findings reveal that a robust ESG performance significantly enhances corporate value by strengthening brand equity and optimizing resource allocation. Intangible assets, particularly brand value, serve as pivotal mediators in translating ESG efforts into market value. Furthermore, the policy environment plays a critical moderating role: state-owned enterprises (SOEs) exhibit amplified ESG-driven value creation due to stronger policy support and resource advantages. Robustness checks, including an instrumental variable analysis, reinforce the reliability of these conclusions, highlighting the interplay of ESG, intangible assets, and policy in driving long-term competitiveness within the sports sector. By addressing the unique dynamics of ESG in the sports industry, this research bridges a gap in the sector-specific literature and underscores ESG’s strategic importance in fostering sustainable business growth. The results provide actionable insights for corporate managers to align ESG strategies with brand development and for policymakers to design targeted frameworks that incentivize sustainable practices.