In this study, we investigate, both theoretically and empirically, the impact of language gender marking on gender wage inequality and country income inequality. We find that nations with a higher level of gender marking in their dominant language have a higher wage gap between genders. Using an instrumental variable approach, we also find that gender marking has an indirect impact on country income inequality via gender wage inequality. Furthermore, we find evidence that the income inequality of a society as a (...) whole is affected by gender wage inequality. Finally, we document that linguistic gender marking outperforms survey-based cultural gender dimensions as a predictor of both gender wage inequality and country income inequality. (shrink)