Previous research has investigated the associations among childhood maltreatment, self-control, and aggression among adolescents without distinguishing between-person effects from within-person effects. Thus, we evaluated the dynamic longitudinal associations among childhood maltreatment, self-control, and aggression, including whether self-control functioned as a mediator of the reciprocal relations between childhood maltreatment and aggression at the within-person level after disentangling between- and within-person associations. A sample of 2050 Chinese early adolescents (43.69% girls, Mage = 10.39 years, SD = 0.55, range = 9 to 12 years at T1) completed measures on 5 occasions across 2.5 years, using 6-month intervals. Random Intercept Cross-Lagged Panel Models were applied to disaggregate between- and within-person effects. RI-CLPMs analysis revealed that at the within-person level: (a) Childhood maltreatment and aggression bidirectionally predicted each other; (b) Childhood maltreatment and self-control bidirectionally predicted each other; (c) Aggression predicted subsequent self-control but not vice versa; (d) Childhood maltreatment did not indirectly predict aggression via self-control and vice versa; (e) Additionally, there were no gender differences observed in the longitudinal associations among childhood maltreatment, self-control and aggression. These findings advanced the literature by elucidating longitudinal associations among childhood maltreatment, self-control, and aggression at the within-person level, highlighting the significance of distinguishing between- and within-person effects in research informing the development of prevention and intervention programs aimed at reducing adolescent aggression.