Online aggressive behavior (OAB) has received increasing attention in recent years, and that playing online violent video games (OVVG) is an important predictor of OAB. However, little is known of the mediating and moderating mechanisms underlying this relationship. This study aims to investigate (a) the mediating role of anger rumination in the association between OVVG and OAB and (b) the moderating role of self-control in the relationship between anger rumination and OAB. A total of 595 Chinese college students (M age = 19.59 years, SD age = 1.40) completed measurements regarding OVVG, anger rumination, self-control, and OAB. The correlation analyses showed that OVVG was significantly positively associated with anger rumination and OAB. Mediation analyses revealed anger rumination partially mediated the link between OVVG and OAB. Moderated mediation further indicated that anger rumination was not associated with OAB for individuals with high levels of self-control. However, for those with low levels of self-control, anger rumination was significantly associated with OAB. These findings suggest that the improvement of self-control and the decline of anger rumination could be a practicable way to address the issue of OAB effectively.