We examined the potential moderating role of Block's personality types (i.e., overcontrollers, undercontrollers, and resilients) on the longitudinal associations between adolescents’ and their best friends’ delinquency. Across three annual waves, 497 Dutch adolescents (283 boys, MAge = 13 years at Wave 1) and their best friends reported on their delinquent behaviors. Adolescents’ three personality types were obtained by latent class growth analysis on their annual reports on Big Five personality. A three-group cross-lagged panel analysis was performed on three waves of data. Delinquency of overcontrollers was predicted by their best friends’ delinquency, whereas delinquency of undercontrollers and resilients was not. Delinquency of undercontrollers and resilients predicted their best friends’ delinquency, but overcontrollers’ delinquency did not. These findings suggest that personality may play an important role in adolescents’ susceptibility to the influence of friends’ delinquency, as well as in youths’ ability to influence friends through their own delinquency.