In classrooms, the work of critical literacy often happens within moment-to-moment and improvised interactions, despite teachers’ planned lessons. These critical literacy moments can be opportunities for constructive dialogue or they can be missed opportunities that are not taken up by teachers and students for a variety of reasons. The purpose of this chapter, then, is to explore critical literacy as situated moments within classroom interactions. To do that, we draw on Dewey’s concept of transactional realism to investigate classroom talk within critical literacy moments in a grade 6 Swedish classroom and in high school classroom in the United States. Findings suggest, while critical literacy in a more traditional understanding is easier for teachers to plan, conduct and evaluate, critical literacy as critical moments are important for teachers who strive to make the classroom a critical environment for the students.