This study addresses a new area of research in Saudi Arabia. Using a sample of 630 Saudi students, it investigates learners’ level of autonomy and its relationship to academic achievement in English as a foreign language (EFL). Learners’ level of autonomy was measured by a survey, whereas their achievement was evaluated using standardized achievement tests. The data were analyzed using descriptive analyses and a t-test. The findings revealed that learners were non-autonomous, with a mean autonomy score of 2.35 out of 5; and also low language achievers (M = 66 out of 100). Gender had a significant effect on autonomy and achievement. These findings emphasize the vast lack of awareness of the vital role of learner autonomy in the Saudi EFL setting. The study suggests that Saudi learners and teachers alike require increased awareness of the importance of the concept of autonomy and that practical means to promote Saudi EFL learner autonomy should be sought and practiced.