ABSTRACTEnglish Learners (ELs), students from non‐English‐speaking backgrounds, are a fast‐growing, understudied, group of students in the U.S. with unique learning challenges. Cognitive flexibility—the ability to switch between task demands with ease—may be an important factor in learning for ELs as they have to manage learning in their non‐dominant language and access knowledge in multiple languages. We used functional MRI to measure cognitive flexibility brain activity in a group of Hispanic middle school ELs (N = 63) and related it to their academic skills. We found that brain engagement during the cognitive flexibility task was related to both out‐of‐scanner reading and math measures. These relationships were observed across the brain, including in cognitive control, attention, and default mode networks. This work suggests the real‐world importance of cognitive flexibility for adolescent ELs, where individual differences in brain engagement were associated with educational outcomes.