Lower socioeconomic status (SES) groups are at heightened risk of exposure to adversity, with early adverse experiences associated with less optimal neurocognitive development, which has downstream effects on education, work, and health indices. Maternal stress is similarly cited to negatively influence infant development. Given the myriad of stressful experiences more common in lower SES contexts, this review sought to understand whether maternal stress drives differences in infant neurocognition between SES groups. Four databases were systematically searched in line with PRISMA guidelines. Fourteen studies were eligible for inclusion, of which twelve reported infant neurocognitive development to be negatively associated with maternal stress, while ten reported positive associations with SES. Nine studies examined the relationship between stress and SES, with six supporting an interactive effect between maternal stress and SES, although the strength and direction of this relationships varied. Gaps in the current research regarding infant brain responses and research into lower income settings, were identified.