The author examines the role of domestic gender equality in predicting whether or not a state is more aggressive in international disputes. This research adds to a growing body of feminist research in international relations, which demonstrates that states with higher levels of gender equality exhibit lower levels of violence during international disputes and during international crises. Many scholars have argued that a domestic environment of inequality and violence results in a greater likelihood of state use of violence internationally. This argument is most fully developed within feminist literature; however, research in the field of ethno-nationalism has also highlighted the negative impact of domestic discrimination and violence on state behavior at the international level. Using the MID data set and new data on first use of force, the author tests, using logistic regression, whether states with higher levels of gender equality are less likely to be aggressive when involved in international disputes, controlling for other possible causes of state use of force. Beyond this project’s contribution to the conflict literature, this research expands feminist theory by further incorporating it into traditional international relations theory to deepen our understanding of the impact of domestic gender equality on state behavior internationally.