["Business Ethics, the Environment &Responsibility, EarlyView. ", "\nABSTRACT\nThe purpose of this paper is to study the differences and similarities between emerging market multinationals (EMNEs) and developed market multinationals (DMNEs) in their levels of adoption of environmental management policies and environmental disclosure practices when they increase their international diversification. This paper builds on a panel dataset consisting of 227 MNEs from 44 countries over the period 2010–2024, employing fixed‐effects panel regression models to test our hypotheses. Our findings reveal that EMNEs and DMNEs exhibit both similarities and differences in their environmental strategies within a global context. Although EMNEs show levels comparable to DMNEs in terms of environmental management policies and environmental disclosure practices, DMNEs exhibit a sharp increase in both environmental strategies as they increase their international diversification. These differences are particularly evident in environmental disclosure, with DMNEs showing a stronger response to transparency demands from home‐country stakeholders. This study contributes to the literature on environmental sustainability in EMNEs and DMNEs by providing a comprehensive understanding of how MNEs address climate change challenges to achieve environmental legitimation in foreign markets. Furthermore, it offers managerial and policy implications, suggesting that policymakers should implement supranational sustainability measures targeting the global operations of MNEs, particularly EMNEs. It also advocates for incentivizing higher levels of international diversification, as this enhances MNEs' environmental management policies and disclosure practices.\n"]