English proficiency is crucial for academic success in institutions where English is the main language of instruction and for career success in countries where English is the primary language of communication. In the U. S., data from the Institute of Educational Sciences shows that 9.2% (an estimated 4.4 million students) were classified as English language learners (ELL) in the academic year 2012–13, up from 8.7% in 2002–03.  Research shows that ELL Students perform lower than non-ELL students in science and English (where the demand for language proficiency is higher).  Similar to the criterion used by the Office of English Language Acquisition (OELA) in the U.S., we categorized ELL students as those who do not speak English language frequently at home.  Using data on about 7,000 students, we assessed the English language achievement gap (E-LAG) on the ACT Science and ACT English tests between ELL students (10% of sample data) and non-ELL students.  The assumption underlying this study is that E-LAG is related to psychosocial factors, whose examination may constitute a potentially fruitful extension of existing research.  After adjusting for high school grade point average (HSGPA) and school effect on achievement, we found that academic self-confidence (the extent to which students believe that they can perform well in school) mediated E-LAG between ELL and non-ELL students.  Specifically, ELL students who were more academically self-confident demonstrated an E-LAG reduction of 52% in ACT Science and 23% in ACT English, relative to ELL students who were academically less confident.  ELL students may be more susceptible to low self-confidence given their limited English proficiency.  Providing interventions to ELL students to bolster not only their academic deficiencies but also their lower self-confidence could potentially help reduce and/or eliminate the E-LAG that currently exists today in the U.S.