["Infant and Child Development, Volume 35, Issue 3, May/June 2026. ", "\nABSTRACT\nLower socioeconomic status (SES) groups are at heightened risk of exposure to adversity, with early adversity associated with less optimal neurocognitive development, which in turn has consequences for later education, work and health. Maternal stress is similarly cited as negatively associated with infant development. Given the various stressful experiences more common in lower SES contexts, this review sought to understand whether maternal prenatal or postnatal stress mediates or moderates the association between SES and infant neurocognitive development. Four databases were systematically searched in line with PRISMA guidelines. Fifteen studies were eligible for inclusion, of which two examined prenatal maternal stress, two both pre‐ and postnatal stress and 11 postnatal maternal stress. Among the prenatal studies, only one tested for mediation, with no evidence that prenatal maternal stress mediated the link between SES and infant neurocognition. Likewise, two other prenatal studies reported no moderation of the stress–infant neurocognition relationship by SES. Of the postnatal studies, only two examined whether maternal postnatal stress mediated any SES‐infant neurocognition association, with contrasting results. Further studies reported negative correlations between stress and SES. Gaps in the current research regarding mediation analyses, infant brain responses and research into lower income settings were identified.\n"]