["Corporate Social Responsibility and Environmental Management, EarlyView. ", "\nABSTRACT\nThis study examines the relationship between sustainability expenditures and Environmental, Social, and Governance performance, emphasizing the moderating role of Financial Reporting Quality, proxied by value relevance and income smoothing. Using a panel of 1770 firm‐year observations from 177 industrial, energy, and basic materials firms in the United Kingdom over the period 2014–2023, the study employs Fixed Effects regressions as the main estimation strategy, complemented by Heckman correction for sample selection bias and GMM to address potential endogeneity. The results indicate that Environmental Expenditure, Environmental Expenditure Investments, and Research and Development expenditures have a positive and significant impact on ESG performance. This effect is significantly moderated by FRQ; value relevance amplifies the impact of sustainability expenditures, while income smoothing supports long‐term strategic consistency. These findings highlight the importance of transparent, informative reporting to enhance the effectiveness of sustainability investments. The study contributes to the ESG literature by showing that sustainability expenditures function as strategic investments rather than mere costs. From a practical perspective, the results suggest that managers should align sustainability strategies with high‐quality financial reporting practices, while policymakers should promote clearer disclosure standards to improve ESG outcomes.\n"]