Mother-child closeness, a mutually trusting and affectionate bond, is an important factor in shaping positive youth development. However, little is known about the neural pathways through which mother-child closeness are related to brain organization. Utilizing a longitudinal sample primarily from low-income families (N=181; 76% African American youth and 54% female), this study investigated the associations between mother-child closeness at ages 9 and 15 and structural connectivity organization (network integration, robustness, and segregation) at age 15. The assessment of mother-child closeness included perspectives from both mother and child. The results revealed that greater mother-child closeness is linked with increased global efficiency and transitivity, but not modularity. Specifically, both the mother’s and child’s report of closeness at age 15 predicted network metrics but report at age 9 did not. Our findings suggest that mother-child closeness is associated with neural white matter organization, as adolescents who experienced greater mother-child closeness displayed topological properties indicative of more integrated and robust structural networks.