Grounded in ecological theory, this study investigated relative contributions of perceived classroom and school climate variables to mathematics self-concept and achievement of English-at-home and English learner (EL) students using PISA 2012 data for American middle-grade students. For both outcomes, results of 3-step hierarchical linear regression models for the combined sample closely mirror those of English-at-home students and mask the unique characteristic of ELs. For self-concept, six ("classroom management," "cognitive activation," "disciplinary climate," "teacher support," "sense of belonging," "and teacher student relations") out of seven predictors were statistically significant and positive predictors for English-at-home students ("teacher support" being the strongest); only two predictors ("disciplinary climate," and "teacher student relations") were significant and positive for ELs. Similarly, group discrepancies were found for mathematics achievement. Five variables ("classroom management," "teacher support," "disciplinary climate," "sense of belonging to school," and "teacher student relations"), were significant predictors of English-at-home students. Yet, only three variables ("classroom management," "disciplinary climate," and "teacher support") significantly predicted achievement of ELs. Classroom climate was consistently an important predictor across outcomes and student populations and was the strongest contributor for ELs. Implications and future directions are discussed.