Difficulties with emotion regulation can take many forms, including increased sensitivity to emotional cues and habitual use of maladaptive cognitive or behavioral regulation strategies. Despite extensive research on emotion regulation and youth adjustment, few studies integrate multiple measures of emotion regulation. The present study evaluated the underlying structure of emotion regulation processes in adolescence using both task- and survey-based measures and determined whether differences in these emotion regulation latent factors mediated the association between peer victimization and internalizing psychopathology. Adolescents aged 16–17 years (n = 287; 55% female; 42% White) recruited in three urban centers in the United States completed baseline and follow-up assessments 4 months apart. Three models of emotion regulation were evaluated with confirmatory factor analysis. A three-factor model fit the data best, including cognitive regulation, behavioral regulation, and emotional reactivity latent factors. Task-based measures did not load onto these latent factors. Difficulties with behavioral regulation mediated the association between peer victimization and depression symptoms, whereas cognitive regulation difficulties mediated the association with anxiety symptoms. Findings point to potential targets for intervention efforts to reduce risk for internalizing problems in adolescents following experiences of peer victimization.