Teachers in all subject areas, including English, must impart the methodology of critical thinking to their students. One of the 21st century's skills is this idea. Teachers must integrate the idea of critical thinking into their lessons. This study aims to analyze how well EFL teachers in Indonesia integrate critical thinking, taking into account learning design, learning resources, conceptual mastery, implementation, and assessment. EFL teachers from junior and senior high schools made up the 120 respondents in this survey, which was used as the research technique. The EFL instructors polled have all completed professional certification training. According to the findings, up to 77.47% of teachers created lesson plans that included the idea of critical thinking, and just a small fraction didn't. Up to 77.5% of those who assembled educational materials did so with the idea of critical thinking in mind; 76.6% were open-minded; up to 80% were employed in learning; and up to 68.3% used assessment. The idea of critical thinking has generally been included by teachers into English learning resources and exercises. It is necessary to conduct this research in order to assess the effectiveness of teachers who use critical thinking approaches in the classroom. Each of the topics that have been examined both quantitatively and qualitatively should be able to be articulated in further detail with additional study.