Bias-based bullying (i.e., bullying targeting actual or perceived aspects of one's identity) is a form of interpersonal victimization that has adverse consequences for youth functioning. While research has documented foundational knowledge on bias-based bullying, few studies have incorporated a multilevel longitudinal approach to examining theorized risk and protective factors of this complex phenomenon. The current study addresses this gap by investigating predictors (e.g., school climate and state laws) at multiple social-ecological levels and comparing the magnitude of coefficients. Three data sources were used: (a) data from a sample of adolescents (