The present study concerns longitudinal research on bullying perpetration and peer victimization. A focus is on school factors of school climate (academic support, group support) and school identification (connectedness or belonging), which are conceptualized as related but distinct constructs. Analysis of change on these factors as well as individual well-being across time contributes to understanding bullying behavior. Latent growth modeling was employed to examine the predictors of anxiety, depression, 2 school climate factors and school identification in understanding change in physical and verbal bullying behavior. The sample included 492 Australian school students (means age 15 years, 53.5% male) in Grades 7 to 10 who completed measures over 3 years. Academic support and group support were the strongest predictors of change in bullying and victimization. Positive change in school identification also predicted a decrease in bullying behavior over time. An increase in depression or anxiety across time predicted an increase in rates of both bullying and victimization over time. Future research should continue to examine the complex relationship between individual-psychological and social-psychological variables in impacting on incidence of school-based bullying. On a practical note, school-based intervention programs may benefit from an approach that aims to target the school climate, social identity with the school, and promote individual psychological well-being.