Most Taiwanese student-athletes have trouble developing English as a communication tool; therefore, it is vital to understand their English learning motivation. Research examining non-native English-speaking student-athletes motivation to learn English remains scarce. This study involved 51 elite Taiwanese student-athletes from 18 sports at a national sports training center to help fill this research gap. It employed a mixed-methods approach utilizing quantitative questionnaires, qualitative interviews, and open-ended surveys. Findings revealed that they perceived learning English as necessary; however, their interest in learning English was moderately low. Extrinsic factors were identified as their primary motivation, followed by intrinsic motivation, while they exhibited very low English learning self-efficacy. Active English learners exhibit higher intrinsic motivation and self-efficacy than passive English learners. However, there was no difference in their extrinsic motivation and anxiety levels. When they applied their competitive spirit, active English learners had the potential to transfer extrinsic and intrinsic motivation into an internal drive, which boosted self-efficacy. The present study evidenced that self-efficacy is associated more with intrinsic motivation than extrinsic motivation. Therefore, we urge language teachers to emphasize intrinsic motivation and self-efficacy for student-athletes while transforming them into active English learners.