["Business Strategy and the Environment, EarlyView. ", "\nABSTRACT\nThis study examines how board gender diversity influences the quality of corporate climate impact disclosure, a critical element of firms' environmental transparency. Focusing on UK nonfinancial firms, we draw on gender socialisation and critical mass theories to explore how diverse boards contribute to strategic climate reporting. We develop a novel textual analysis–based index to measure the depth of climate‐related disclosure within annual reports and assess its relationship with board composition. Our findings reveal that board gender diversity significantly enhances the quality of climate disclosures, with boards comprising at least four female directors exerting the strongest positive influence. These results are robust across multiple model specifications, endogeneity checks and diversity measures. By linking board structure to environmental reporting quality, this study advances understanding of how corporate governance can support climate‐related transparency, an issue of growing importance under frameworks such as IFRS S1 and S2. Our work contributes to the literature on sustainability strategy, governance and environmental performance.\n"]