This study investigates how sustainability reporting disclosure relates to earnings management and whether this relationship changes depending on board gender diversity and the effectiveness of the risk committee. Using 590 firm-year observations drawn from Jordanian listed companies, the study estimates the main relationships through pooled ordinary least squares (pooled OLS) regression. The findings indicate a significant negative association between sustainability reporting disclosure and accrual-based earnings management. This suggests that greater sustainability reporting disclosure is associated with less managerial discretion in financial reporting. However, the analysis does not provide statistically significant evidence that board gender diversity or risk committee effectiveness moderates this relationship. The results are robust to alternative earnings management proxies, as similar conclusions are obtained using Kothari-adjusted discretionary accruals and measures of real earnings management. To overcome potential endogeneity and selection issues, additional analyses with the two-step system GMM model yield similar main findings. By focusing on an emerging-market context, the study extends prior research on sustainability and corporate governance and shows that sustainability reporting may serve an important accountability role in strengthening the quality of financial reporting.