Objective: Being a target of homophobic name-calling is associated with adverse outcomes for youth. Few studies have examined homophobic name-calling longitudinally among middle school youth. To address this gap, this longitudinal study examined predictors of changes in homophobic name-calling including bullying, sexual harassment, dismissiveness of sexual harassment, and traditional masculinity over the course of 2 years of middle school. Method: Participants included 1,655 students in 5th–8th grade from 4 public middle schools in the Midwest. The survey assessed demographic characteristics, homophobic name-calling, bullying, sexual harassment, and traditional masculinity across 4 waves of 2 years of data collection. Results: Homophobic name-calling increased over time; however, the rate of acceleration slowed. Higher within-person and between-person bullying was associated with increases in homophobic name-calling, but increases in dismissiveness of sexual harassment and traditional masculinity were not associated with increases in homophobic name-calling. Increases in within-person sexual harassment were associated with contemporaneous increases in homophobic name-calling. Relations between bullying and homophobic name-calling were especially pronounced for those at high levels of dismissiveness of sexual harassment for both within- and between-person models. Conclusion: To effectively address school bullying among early adolescents, it is imperative that antibullying policies and prevention programs work to address homophobic name-calling and dismissiveness of sexual harassment. (PsycINFO Database Record (c) 2017 APA, all rights reserved)