While teachers’ initial education is key to ensuring that new teachers are prepared for their work, it is only one piece in the continuum of teachers’ professional growth. Continuing professional learning is vital for teachers to broaden and deepen their knowledge, keep up with new research, tools and practices and respond to their students’ changing needs. It also plays a key role in building collaborative school cultures and supporting the collective improvement of the teaching profession. While the importance of continuing teacher learning is widely recognised, building efficient, equitable and sustainable professional learning systems is far from trivial. The OECD Teachers’ Professional Learning (TPL) study seeks to support the development of effective TPL policies and practices in schools and school systems. This paper proposes a theoretical and analytical framework for the study, systematically maps available OECD indicators to this framework and identifies information gaps and areas for future comparative work.