Compared with their non-migrant peers, migrant children in China face major risks and challenges that may cause them to develop behavioral and psychological problems. Nevertheless, research has seldom addressed their victimization by bullies and its association with their mental health outcomes, much less the roles of intrapersonal and interpersonal sources of resilience in that relationship. In response, this study was designed to examine how bullying victimization both directly and indirectly influences migrant children’s mental health through intrapersonal and interpersonal sources of resilience. Data were collected from a school-based multistage random sample of 1,132 migrant children in Grades 4–9 (mean age = 11.88 years, range = 8–17 years; boys = 55.6%) attending public schools in Nanjing and private schools in Guangzhou, China. Structural equation modeling performed with Amos 25.0 revealed that both intrapersonal and interpersonal sources of resilience mediated the effect of bullying victimization on migrant children’s mental health, albeit intrapersonal sources demonstrated a slightly stronger mediation effect. The results thus suggest that social workers and educators should provide effective prevention and intervention strategies that promote intrapersonal and interpersonal sources of resilience among migrant children in China.