Although broad associations between socioeconomic status (SES) and child executive functions (EFs) are well established, contextual factors that may matter for effects of SES on EF are not fully understood. This study used a bioecological approach to examine factors that may moderate SES-EF relations. A socioeconomically diverse sample of children ages 4.5-5.5 completed working memory and go/no-go tasks. Parents reported on well-being, household chaos, and neighbourhood chaos. Higher SES related to better working memory performance and higher accuracy on go trials, but neighbourhood chaos moderated these associations. Specifically, for higher neighbourhood chaos, the relations between SES and working memory and go accuracy (indexing general vigilance) were especially pronounced, such that the best EF performance was observed in children in high-SES households who experienced higher neighbourhood chaos. Results highlight the relevance of neighbourhood quality for underlying processes of EF development, particularly in the context of high SES. Further, findings suggest the importance of teasing apart specific contextual factors that matter for child cognitive functioning.