Creative self-regulation (CSR) is important in facing the challenges and uncertainty of creative teaching and learning. Our understanding for how teachers develop creative self-regulation skills and knowledge for the classroom remains limited. This longitudinal case study begins to fill this gap with an in-depth investigation of one U.S. high school teachers' development and application of CSR in relationship to her creative agency in teaching. This study incorporated a variety of data sources to document and understand CSR development for the distinct challenges of creative teaching and facilitation of creative learning. Results indicated the teacher began with a more rigid and dysregulated CSR approach, which developed across 2 years of professional development into a flexible and experimental approach. The teacher demonstrated a strong creative agency and trust in her intuition by the end of the 2 years. Findings suggested the key CSR skills that catalyzed her approach included withholding judgment and releasing control to students. Future research on teachers' creative development and CSR for the classroom can investigate these characteristics further. Results also reinforced the important connection between CSR development and the beliefs, values, and attitudes that formed the teachers' creative agency--another area for future research.