This cross-sectional study examines associations between PreK classroom-level teacher-child interaction quality and individual children's peer engagement quantity and quality. The study utilizes a sample of 714 children from 214 classrooms collected as part of the National Center for Research on Early Childhood Education Professional Development (NCRECE) study. Multilevel regression models using a bifactor analytic approach to measuring teacher-child interaction quality (resulting in three unique and uncorrelated factors) indicate that in classrooms with higher levels of responsive teaching practices, individual children exhibit greater peer sociability and assertiveness, but not communication. In classrooms with higher levels of cognitive facilitation, individual children display higher peer engagement across all measured dimensions (Sociability, Assertiveness, Communication), and greater observed potential for peer communication, operationalized as children's highest observed peer engagement score. Finally, in classrooms with more effective management and routines, individual children display lower peer sociability and assertiveness, but not communication. Implications are suggested for supporting children's peer engagement within early childhood classrooms.