<p>Numerous frameworks have been developed to describe and assess the pedagogical content knowledge of mathematics teachers. The Knowledge Quartet Framework (KQ), with its focus on professional knowledge for mathematics teaching, has received extensive attention and acknowledgment in various studies. This systematic literature review assessed the growth, use, and application of the KQ in mathematics education research. An analysis of 36 peer-reviewed articles showed that the KQ, initially rooted in UK primary mathematics novice teaching practices, has since gained global prominence. Though originally designed for primary education, applications of KQ span from primary to higher education settings, shedding light on relationships between teacher proficiency, content knowledge, and student performance. Furthermore, while the KQ was primarily associated with mathematics teaching, recent trends have seen its application in disciplines ranging from science to physical education. Key areas of KQ application include reflection on practice, coding and observing classroom practices, understanding the transition of pre-service and novice teachers to experienced classroom teachers, lesson planning, and alignment with other educational frameworks. The review highlights the KQ’s role in enhancing teaching practices across various educational levels, its application in diverse research methodologies, and its expanding scope beyond mathematics education.</p>