Structural socioeconomic inequality -the aggregate level unequal distribution of resources and opportunities within a region- significantly impacts brain health. Unlike traditional neuroscience approaches that focus on individual factors, recent studies highlight the biological embedding of macrosocial inequalities. We discuss studies on structural inequality that use EEG and f/MRI across diverse populations. Greater structural inequality is associated with adverse brain outcomes, such as reduced complexity, volume, and connectivity, particularly in temporo-posterior regions. Structural inequality significantly contributes to brain burden, even after accounting for individual demographics, and its effects are more pronounced in aging and dementia. This evidence opens a new framework for studying various physical (e.g., air pollution) and social (e.g., gender inequality, sociopolitical determinants) exposomes at the aggregate level in relation to brain health. Neuroscience can inform policymakers to address the positive brain health impacts of mitigating structural determinants of health through policies that enhance social safety and healthcare access.