Cultivating a culture of higher-order thinking has been one of the desired outcomes in the field of education for many decades. However, the rapid development in technology has recently made critical thinking (hereafter CT) an emphasized 21st century educational goal. This goal changed the role of teachers from transferring information to preparing students for information processing by exercising critical judgment and creative thinking. Like in other fields, the prominence of fostering this skill is acknowledged in English Language Teaching. On the other hand, to what extent prospective English teachers, who are the future gatekeepers in facilitating learners' thinking skills, are aware of the ways they could merge CT with their teaching and how much they could transfer such awareness into practice needs to be investigated. Thus, the present study comprising of an action research design explored the impact of a 14-week action plan implementation on 8 pre-service English teachers' awareness and teaching practices regarding the integration of CT into language teaching. Data collection involved the use of CT tasks, semistructured interviews, lesson plans, video-recorded macro teachings, and self-reflection journals. Both quantitative analysis in the form of descriptive statistics and qualitative analysis in the form of content analysis were performed to scrutinize the results. The findings indicated gradual perceptual improvement about the concept and how to integrate it into language teaching. This was also reflected in teaching practices of the participants thanks to sufficient and appropriate guidance despite some reported external and internal obstacles.