The discourse on teachers as agents of school change has recently emerged in educational policies in many countries, emphasizing teacher-led educational reforms. The meaning of this rhetoric is quite vague; its practical meaning is revealed by analyzing how teachers' roles are normalized in educational policies. With a Foucauldian approach, this study aims to critically analyze teacher images produced and distributed by South Korea's educational reform policies over the last 20 years. This study addresses two research questions: (1) Under the rhetoric of teachers as agents of school change, what teacher images have been created by Korean educational reform policies over the last 20 years? (2) What are the non-discursive conditions that have led to the establishment of the teacher images presented in educational reform policies? To this end, 94 policy documents from the 5 Korean governments were collected and analyzed. The study results verified a contradictory character of policy discourse in that policies stating teachers as agents of school change appear to empower teachers to reform education, which is not true in reality. The results also revealed complex mechanisms enabling certain policy discourses to be formed by analyzing the formation process of particular teacher images produced by educational policies in relation to non-discursive conditions. Furthermore, this study showed that particular teacher images circulated by educational policies can regulate teachers' everyday practices, contributing to understanding the way educational policies exert their power. Finally, the implications of the findings were presented.