Neuroimaging studies suggest that resilience to adversity is linked to reduced emotional reactivity or enhanced emotion regulation. However, such studies are scarce and mainly use adult samples and categorical definitions of resilience. Using a novel, data-driven approach to define resilience dimensionally, based on cumulative adversity exposure across childhood and psychopathology, we investigated associations between resilience and brain activation during facial emotion processing in youth. We also tested for sex differences in the relationship between resilience and brain activation. fMRI data were acquired from 208 youths (aged 9–18 years; Mean age = 13.28), while viewing angry, fearful, and neutral faces. Whole-brain analyses were performed, followed by region-of-interest analyses focusing on the amygdala, hippocampus, and prefrontal cortex. Resilience was positively correlated with bilateral inferior frontal gyrus responses to fearful (versus neutral) faces, and negatively correlated with right superior temporal gyrus, left hippocampal, and right inferior frontal gyrus responses to neutral faces (versus fixation). Sex-by-resilience interactions were observed in the medial prefrontal cortex: males showed positive, while females showed negative, associations between resilience and brain activation, though these results did not survive correction for multiple comparisons. These findings provide further evidence that resilience in youth is associated with enhanced emotion regulation at a neural level.