Definitions of teaching quality differ across jurisdictions and have evolved over time. Drawing on a study of five high-achieving countries with strong supports for teachers' professional learning and practice, this article describes the perspectives on good teaching rooted in standards for entry, preparation, and practice. These nations increasingly see teaching as rooted in a wide-ranging knowledge base that combines an understanding of content, pedagogy, and learners to focus on meeting students' diverse social, emotional, and academic needs. These jurisdictions also define teaching quality as rooted in ongoing research and inquiry on the part of teachers -- a means of developing knowledge for teaching that is at the core of professional practice.