Using a three-wave (mean age 14.4, 17.4, and 20.4 years) longitudinal design (N = 1,834; 55.6% females), we set out to map direct and indirect effects of adolescent peer victimization and mental health on academic achievement in early adulthood, and the buffering effect of positive family relations. Data was collected in Sweden 2012 to 2018. We found concurrent ([beta]s = 0.13-0.28) but no longitudinal transactional effects between peer victimization and symptoms of depression, anxiety, and conduct disorder (CD). Peer victimization, depression, and CD had longitudinal direct effects on poorer academic achievement in early adulthood ([beta]s = 0.09-0.11). Positive family relations did not moderate the effects. The results indicate that prevention and interventions against peer victimization and poor mental health may contribute to a higher proportion of individuals graduating from high school.