Learner autonomy is a way to promote students to perform their learning ability effectively and it is essential for students to acquire this skill for a lifelong learning journey. The present study aimed to investigate the learner autonomy level and observe in detail language learning strategies use of Thai EFL learners comparing international school students and Thai public-school students in a tutorial school in Bangkok. 200 senior high school level students, 100 international school students and 100 Thai public-school students, in a tutorial school participated in the study. The study design is mix-method research. A learner autonomy questionnaire and the Strategy Inventory for Language Learning (SILL) questionnaire by Oxford (1990) were the quantitative data collection instruments in this study. Interviews were conducted for more information in detail as qualitative data collection. The data analysis was carried out through quantitative analysis techniques. The findings from the learner autonomy questionnaires revealed that Thai public school students have a higher level of learner autonomy. Moreover, the findings from the SILL questionnaires also showed that Thai public school students employ language learning strategies more than the international school students. The cognitive strategies are mostly employed by the international school students whereas the compensation strategies are widely used by Thai public school students.