Objective Income inequality scholars suggest that extreme income inequality leads to spatial segregation, political power concentrated in the high‐income (elite) class, and thus, uneven public resource access. This work argues that income inequality may also predict higher levels of vulnerability of urban municipalities to climate‐related hazards. Method Using factor analysis and multilevel regression models, this research tests whether income inequality is a predictor of vulnerability to flood hazards. Results The analysis shows that income inequality significantly predicts higher levels of a key component of vulnerability in urban Brazilian municipalities. Conclusion By providing empirical evidence for the theorized linkages between income inequality, spatial segregation, and uneven public resource access, this work bolsters the claims of income inequality scholars who suggest high levels of income inequality have negative social consequences. Additionally, this work is relevant to climate change vulnerability scholars as it underscores the importance of considering income inequality as part of urban climate change vulnerability assessments.