This study investigated the relationship between autonomy and critical thinking in speaking ability among EFL students at Islamic Azad university of Shiraz. To this aim, three types of instruments were applied to collect research data, i.e. Zhang and li's learner autonomy questionnaire, Watson-Glaser Critical Thinking Appraisal as well as a final achievement exam administered at the end of the term to collect students' English speaking grades. For the analysis of the data, correlation method was employed .Significance level of 0.05 was considered for testing the hypotheses. The findings indicated that there was a significant relationship between speaking ability and autonomy. Also, there was a positive relationship between speaking ability and critical thinking .In fact, those English learners who were recognized as critical thinkers and autonomous performed better in their oral production.