Action research is a research method applied by teachers and school administrators, especially in the field of education, to solve practical problems and improve teaching-learning processes. Originating in the work of Kurt Lewin, action research involves a spiral process consisting of planning, action, observation and reflection stages. This method allows teachers to critically evaluate and improve their own classroom practices. Action research, which can be examined under three headings, each based on different philosophical foundations: technical, applied and liberating, is practice-oriented, unlike traditional research methods, and requires direct participation of teachers. During the research process, teachers work in collaboration with students and other stakeholders to develop solutions for a specific problem and implement these solutions. The importance of action research in education is that it contributes to the professional development of teachers, improves students' learning processes and increases the overall quality of the school. This method encourages teachers to think critically and focus on continuous improvement. In addition, action research represents a democratic approach and is carried out with the participation of many stakeholders. This method, which is an effective tool for managing change and transformation processes in educational organizations and improving teaching-learning processes, contributes to the professional development of teachers and school administrators, while also helping to increase students' academic success. In this section, the historical development of action research, its definition, its importance, and its comparison with traditional research methods are discussed in detail. In addition, different types and models of action research are examined, and examples of how this method can be applied in education are presented.