AbstractObjective:The current study aimed to explore the interplay between food insecurity, fast-food outlet exposure and dietary quality in disadvantaged neighbourhoods.Design:In this cross-sectional study, main associations between fast-food outlet density and proximity, food insecurity status and dietary quality were assessed using Generalized Estimating Equation analyses. We assessed potential moderation by fast-food outlet exposure in the association between food insecurity status and dietary quality by testing for effect modification between food insecurity status and fast-food outlet density and proximity.Setting:A deprived urban area in the Netherlands.Participants:We included 226 adult participants with at least one child below the age of 18 years living at home.Results:Fast-food outlet exposure was not associated with experiencing food insecurity (fast-food outlet density: b = −0·026, 95 % CI = −0·076; 0·024; fast-food outlet proximity: b = −0·003, 95 % CI = −0·033; 0·026). Experiencing food insecurity was associated with lower dietary quality (b = −0·48 per unit increase, 95 % CI = −0·94; −0·012). This association was moderated by fast-food outlet proximity (P_interaction = 0·008), and stratified results revealed that the adverse effect of food insecurity on dietary quality was more pronounced for those with the nearest fast-food outlet located closer to the home.Conclusions:Food insecurity but not fast-food outlet density is associated with dietary quality. However, the association between food insecurity and dietary quality may be modified by the food environment. These findings could inform policymakers to promote a healthier food environment including less fast-food outlets, with particular emphasis on areas with high percentages of food insecure households.