We analyzed a population-based cohort of 11,780 U.S. children to identify risk and protective factors by kindergarten predictive of being frequently verbally, social, reputationally, or physically victimized during the upper elementary grades. We also stratified the analyses by biological sex. Kindergarten children displaying externalizing problem behaviors were at consistently higher risk of being frequently victimized during 3rd-5th grade (odds ratios [OR] for verbal = 1.82, social = 1.60, reputational = 1.85, physical = 1.67, and total = 1.93). Hispanic children (OR range = 0.51 to 0.68) and those from higher income families (OR range = 0.73 to 0.83) were less likely to experience victimization. Boys were more likely to be physically bullied (OR = 1.38) but less likely to be verbally (OR = 0.83), socially (OR = 0.66), or reputationally (OR = 0.83) victimized or to experience total victimization (OR = 0.82) than girls. Other variables predictive of increased risks for frequent victimization included having a disability, experiencing cognitively stimulating parenting, and displaying lower academic achievement. [This paper was published in "School Mental Health" v14 2022.]