The Trends in International Mathematics and Science Study (TIMSS) assesses mathematics and science knowledge of fourth and eighth grade learners worldwide. South Africa has participated in six of the seven TIMSS cycles (1995–2019), at the eighth or ninth grade, providing a rich dataset spanning 24 years. Participation in TIMSS allows countries to evaluate their learners’ achievements and compare their achievements with other countries, as well as monitor the health of their education systems over time. In addition, the study allows the exploration of how various contextual factors are associated with mathematics and science achievement.