Modern-day corporations are under intense stakeholder pressure to incorporate environmentalism, particularly biodiversity initiatives, into their business strategy. Building on upper echelon and gender socialization theories, we investigate the effect of board gender diversity (BGD) on the biodiversity initiatives undertaken by firms for the restoration and rehabilitation of damaged ecosystems and/or to minimize their environmental impacts. Using data on 2406 US firms covered in the ASSET4 database for the period 2002–2018 (15,337 firm-year observations), we document a significant positive association between BGD and both biodiversity restoration protection and impact reduction initiatives. Our findings are consistent for exploitative and nonexploitative industries, as well as for the pre-and post-UN resolution on conservation of biodiversity periods. We further develop a causal relationship through the positive impact of BGD on management environment training and environmental partnerships—possible mechanisms by which BGD may impact biodiversity initiatives. The results suggest that BGD is vital for developing strategies concerning the restoration, protection, and impact reduction of biodiversity and ecosystems. Our findings are of interest to legislators and regulators who are interested in assessing biodiversity initiatives, improving environmental policies, and promoting gender diversity in company director boards.