This study addresses the persistent decline in learner performance and engagement in Mathematics and Science in South African secondary schools by exploring Communities of Practice (CoP) as an alternative framework for teacher preparation and development. Using a comprehensive literature review and thematic analysis of international and local research, the study examined the principles, implementation strategies, and outcomes of CoP-based teacher education. The findings indicate that effective Mathematics and Science teacher development depends on five key elements: situated learning in authentic school contexts, sustained collaboration among educational stakeholders, integration of content and pedagogical knowledge through reflective practice, development of teacher agency and professional identity, and strong alignment between universities and schools. Based on these findings, the study proposes a comprehensive CoP model that integrates initial teacher education, induction, and continuous professional development. The study concludes that improving Mathematics and Science education in South Africa requires a shift from traditional theory-driven teacher preparation towards collaborative, practice-based learning systems supported by appropriate institutional structures, funding mechanisms, and policy frameworks.