A latent profile analysis was applied to explore heterogeneity in the social and classroom behaviors of 224 peer-rejected elementary school students (56% White, 68% male, Grades 1-4, M age = 8.1 years). Profile indicators included teacher ratings of social skills and problem behaviors on the Social Skills Improvement System (SSIS) and peer nominations of prosocial, aggressive, and withdrawn behavior. Four profiles emerged. Two profiles where characterized by elevated externalizing problems by peer and teacher report, one with multiple co-occurring difficulties (multiproblem, 21% of the sample) and one characterized primarily by aggression (domineering, 32% of the sample). Another profile was characterized by deficits in social skills and viewed by teachers as internalizing and disruptive (internalizing-dysregulated, 26% of the sample.) The final profile was nondistinct on teacher ratings but defined by low rates of prosocial behavior by peers (teacher preferred, 21% of the sample.) Group comparisons revealed that students in the multiproblem and internalizing-dysregulated profile classes had lower-quality relationships with teachers and more academic difficulties than students in the other two profile classes. The findings are discussed in terms of implications for identifying peer-rejected students for Tier 2 interventions and tailoring those interventions to enhance impact. [For the corresponding grantee submission, see ED622111.]