ABSTRACT Supporting teachers’ agency is essential for implementing inclusive education, as agentic teachers tend to take more responsibility for making a change and focus more on activities that benefit the children they teach. Lack of teacher agency might be one of the reasons why inclusive education has not been applied successfully in kindergartens. In our study, we focused on supporting teacher agency for inclusive education according to the ecological model of agency. Our approach to inclusive education was drawn from the holistic model of inclusive education. We developed an in-service training program to support the three dimensions of agency across different levels outlined in the model of the implementation of inclusive education. The aim of this study was to explore the improvement in participants’ agency during the in-service training program. We applied pre- and post-questionnaires to explore the agency of kindergarten staff members who attended the in-service training program. The results showed statistically significant changes in kindergarten staff’s agency in the iterational and projective dimensions of agency in implementing inclusion. Therefore, we can conclude that a long-term team-based in-service course is effective in supporting teacher agency related to inclusion.