Victimization is linked to externalizing outcomes in adolescents and recent theorizing suggests that sleep plays a role in this relationship; however, there is little evidence examining sleep as a mediator. This study examines associations between victimization experiences and changes in aggression, delinquency, and drug use. Data were obtained from three waves of a school-based study with middle-school youth (n = 785; 55 % female; 20 % African American; M = 12.32, SD = .51 years at T1), and path analyses were used to test the key hypotheses. Analyses controlling for major life events, demographic factors, and school site revealed that victimization indirectly affected delinquency and drug use, but not aggression, through its relationship with sleep problems. Further, the effects of sleep problems on drug use were specific to females. These data suggest that intervening to address sleep problems resulting from victimization may serve to reduce some forms of externalizing behavior.