Within a national sample of Spanish-English dual language learner (DLL) children enrolled in Head Start, this study examined how classroom language context and emotional support quality are related to changes in approaches to learning and social skills. Specific aspects of the learning context that were examined in relation to children’s school readiness were proportion of Spanish-speaking classroom peers, teacher’s instructional use of Spanish, and children’s English proficiency at the start of the school year. Multilevel modeling results revealed a significant positive association between the percent Spanish-speaking classroom peers and approaches to learning, accounting for child- and classroom-level characteristics, and other aspects of the classroom language context. There were no significant associations between aspects of the classroom language context and social skills outcomes, and in no models was emotional support quality a significant predictor. Additional analyses of potential interactive effects suggested that peer language match is especially important for Spanish-English DLLs who may otherwise experience English-dominant teacher-child interactions (either because their teacher instructs in English only and/or the child is proficient in English). In other words, peers may provide important Spanish language or bilingual interaction opportunities when these are not available via bilingual teacher-child interactions. Findings also indicated that DLL children’s English proficiency status moderated the effects, underscoring the need for research to consider heterogeneity among Latine preschoolers (Ansari, 2017; Castro et al., 2013). Implications for ECE practices and future research are discussed. (author abstract)