This paper examines how and to what extents critical thinking-based EFL lessons helped facilitate Thai EFL students’ language learning and their engagement in their fundamental English course for the undergraduate program. The investigation focuses on a qualitative study on the teaching practice of critical thinking-based EFL lessons at the tertiary level. Data were collected through classroom observations and collection of relevant documents—written assignments and tests. The analysis focuses on data pertaining to the informants’ language performance and student learning toward this particular teaching practice. The findings show that critical thinking-oriented EFL lessons, to a large extent, empowered the students’ EFL learning. The observed classroom culture, coupled with written tasks discloses that they felt no longer disenfranchised. The teaching approach initiated access to the target language use and the personal “voice” development. Most of the students were fully engaged and willing to take extra steps in their language learning, thus creating a lively learning atmosphere where students actively participated in the classroom activities and co-constructed their language learning. However, the language gain over the year was marginally significant. The study contributes to our understanding and the curriculum design in facilitating EFL students’ language learning in the fundamental English course where critical thinking-related lessons can be incorporated. The findings also provide suggestions on how EFL teachers can help prepare a global citizen in responding to social challenges in a knowledge-based society of the 21st century.