Abstarct: Teacher autonomy has long been a topic of interest in the field of applied linguistics. The overall objective of this research is to investigate Iranian EFL teachers’ perceptions of the concept of teacher autonomy. This study aims to investigate and compare how Iranian English language teachers at public schools and private language institutes perceived the concept of teacher autonomy and how it is exercised in relation to four areas of teacher activity: pedagogy, school management, professional development and curriculum development. To investigate the concept of teacher autonomy, a quantitative method was used. In order to examine the participants’ perceptions of teacher autonomy (N=137), a questionnaire (α= .86) was integrated from Friedman (1999) and Pearson & Hall (1993) and was utilized in this study. Chi-square tests and frequency counts were used to examine whether the teachers’ perceptions of teacher autonomy in the two sectors were significantly different. The findings revealed that their perceptions were not significantly different in areas of pedagogy (.8 > .05), and school management (.84 > .05). Moreover, the data showed that the participants’ perceptions were significantly different in areas of professional development (0.00 < .05) and curriculum development (0.00 < .05). Finally, this study concludes with highlighting the importance of autonomy in teacher training programs and some theoretical and practical implications are proposed. The outcomes of this research have implications for our understanding of teacher autonomy in the field of applied linguistics and for improving the quality of English language teaching in Iran.