Objective: The aim of this study was to investigate the association between school connectedness and performance in standardized test scores and whether this association was moderated by ethnic private regard. Method: The study combines self-report data with school district reported data on standardized test scores in reading and math and free and reduced lunch status. Participants included 436 Mexican-origin youth attending a middle school in a southwestern U.S. state. Participants were on average 12.34 years of age (SD = .95) and 51.8% female and 48.2% male. Results: After controlling for age, gender, free and reduced lunch status, and generational status, school connectedness and ethnic private regard were both positive predictors of standardized test scores in reading and math. Results also revealed a significant interaction between school connectedness and ethnic private regard in predicting standardized test scores in reading, such that participants who were low on ethnic private regard and low on school connectedness reported lower levels of achievement compared to participants who were low on ethnic private regard but high on school connectedness. At high levels of ethnic private regard, high or low levels of school connectedness were not associated with higher or lower standardized test scores in reading. Conclusion: The findings in this study provide support for the protective role that ethnic private regard plays in the educational experiences of Mexican-origin youth and highlights how the local school context may play a role in shaping this finding.