This research focuses on the standardization mechanism for teachers' continuous professional development as a key factor in improving education quality. Research shows that teacher competence directly affects student success and depends on systematic professional development of educators. Analysis of international experience (Kazakhstan, Australia, United Kingdom, Canada, Scotland, Singapore, Estonia) demonstrates that the most effective standardization tool is the Professional Standard integrated into a unified teacher assessment system. Accordingly, the research aimed to analyze international experience, research and empirical data to justify the relevance of developing standard frameworks for professional development and to argue the choice of methodology, concept, and structure of the Professional Standard. The methodological foundation comprised scientific examination of the existing Professional Standard in the national education system, as well as analysis, synthesis, and systematization of scientific data. The study justified the need to transform disparate short-term activities into a unified system of teachers' continuous professional development and revealed the potential of the Professional Standard as an objective tool for teaching quality assessment.