This study had 2 objectives: Our first objective was to provide the first evidence of developmental trends in victimization rates for lesbian, gay, and bisexual (LGB)- and heterosexual-identified youth, both in absolute and relative terms, and to examine differences by gender. Our second objective was to examine links between victimization, sexual identity, and later emotional distress. Data are from a nationally representative prospective cohort study of youth in England were collected annually between 2004 and 2010. Our final analytic dataset includes 4135 participants with data at all 7 waves; 4.5% (n = 187) identified as LGB. Analyses included hierarchical linear modeling, propensity score matching, and structural equation modeling. LGB victimization rates decreased in absolute terms. However, trends in relative rates were more nuanced: Gay/bisexual-identified boys became more likely to be victimized compared with heterosexual-identified boys (wave 1: odds ratio [OR] = 1.78, P = .011; wave 7: OR = 3.95, P = .001), whereas relative rates among girls approached parity (wave 1: OR = 1.95, P = .001; wave 7: OR = 1.18, P = .689), suggesting different LGB-heterosexual relative victimization rate trends for boys and girls. Early victimization and emotional distress explained about 50% of later LGB-heterosexual emotional distress disparities for both boys and girls (each P < .015). Victimization of LGB youth decreases in absolute, but not necessarily relative, terms. The findings suggest that addressing LGB victimization during adolescence is critical to reducing LGB-heterosexual emotional distress disparities but additional support may be necessary to fully eliminate these disparities.