This study explores the intricate interplay between female representation in national parliaments and government fiscal policies, with a specific focus on fossil fuel subsidies, environmental taxes, and expenditure, in the context of climate change mitigation. Using a sample of 160 countries over the period from 1997 to 2022, this empirical analysis demonstrates the positive relationship between the presence of female parliamentarians and environmentally friendly fiscal measures. While women in the parliaments reduce the amount of the subsidies granted to fossil fuels, they levy environmental taxes and increase environmental spending. The findings illustrate the pivotal role of female parliamentarians in advocating for environmental legislation and transcending political ideologies and national boundaries. Addressing potential concerns of endogeneity by employing additional control variables, omitted variables, and instrumental variable analyses, this study emphasises the robustness of the results. Notably, this study finds that a critical mass of at least 30% female representation in parliaments enhances the efficacy of environmental policy outcomes. This research highlights the multifaceted impact of gender diversity on fiscal policies related to environmental protection, offering valuable insights for policymakers and organisations committed to sustainability and gender equality.