Neighborhood disadvantage has consistently been linked to alterations in brain structure; however, positive environmental (e.g., positive parenting) and psychological factors (e.g., temperament) may buffer these effects. We aimed to investigate associations between neighborhood disadvantage and deviations from typical neurodevelopmental trajectories during adolescence, and examine the moderating role of positive parenting and temperamental effortful control (EC). Using a large dataset (n = 1313), a normative model of brain morphology was established, which was then used to predict the age of youth from a longitudinal dataset (n = 166, three time-points at age 12, 16, and 19). Using linear mixed models, we investigated whether trajectories of the difference between brain-predicted-age and chronological age (brainAGE) were associated with neighborhood disadvantage, and whether positive parenting (positive behavior during a problem-solving task) and EC moderated these associations. We found that neighborhood disadvantage was associated with positive brainAGE during early adolescence and a deceleration (decreasing brainAGE) thereafter. EC moderated this association such that in disadvantaged adolescents, low EC was associated with delayed development (negative brainAGE) during late adolescence. Findings provide evidence for complex associations between environmental and psychological factors, and brain maturation. They suggest that neighborhood disadvantage may have long-term effects on neurodevelopment during adolescence, but high EC could buffer these effects.