The association between perfectionism and addictive behaviors has been examined in previous literature; however, few pieces of research have investigated the mediating and moderating mechanisms underlying this relationship. Using a sample of 2016 Chinese college students, the present study examined the mediator of depression between maladaptive perfectionism and Internet addiction and the moderator of gender in such associations. The findings indicated that maladaptive perfectionism was directly related to students’ Internet addiction and indirectly predicted students’ Internet addiction via the mediator of depression. Gender moderated the direct effect, rather than the indirect effect, of maladaptive perfectionism on Internet addiction. Even though males reported a lower score on Internet addiction compared to females, the effect of maladaptive perfectionism on Internet addiction was stronger for males than for females. These findings revealed the psychological mechanisms from perfectionism to Internet addiction, which contributed to the theoretical development in addiction research and provided implications for interventions to reduce Internet addiction among Chinese college students.