Improving the Quality of Teaching and Student Learning in Secondary STEM Education in Rwanda, 2019-2023 includes data collected by a study aimed at generating evidence of improved teaching and learning for the Leaders in Teaching (LIT) initiative. The LIT initiative aims to improve the quality of teaching and learning outcomes in Rwandan secondary schools. The LIT initiative includes several interventions, centred around four pillars: recruit, train, lead, and motivate. The initiative is implemented in 14 out of 30 districts in Rwanda, selected based on lowest Lower Secondary Leaving Examination results, the highest gender gap in learners’ pass rates on these exams, and the highest percentage of dropouts. As learning partners, the REAL Centre and Laterite collected data (2019-2023) to track changes on schools affected by this program. Five research instruments were used: 1. School leader survey: to understand and track changes in school leader inputs, motivation, perceptions of their own leadership and teaching quality, and views towards teaching in diverse settings and COVID-19 effects, and more. 2. Teacher survey: to understand and track changes in teacher inputs, motivation, perceptions of their own teaching quality, and views towards teaching, experience with continuous professional development and COVID-19 effects, and more. 3. Teacher Content and Pedagogical Knowledge Assessment: to ascertain content-specific and pedagogical content teacher knowledge. It was developed as a mock grading assignment for teachers. 4. Student Assessment: to understand and track improvements in student learning. The content is the same as the Learning Achievement in Rwandan Schools (LARS3) numeracy test. Additionally, the assessment also included a survey to collect background information on students. 5. Classroom Observations: to understand and track improvements in teaching processes and practices. It covers domains of teaching practice, e.g. classroom culture, instruction, socio-emotional skills. Instrument 1 and 2 were deployed at 358 schools. Instruments 3-5 were applied to a subsample the 'learner schools' - of around 100 schools. Education; health; equity; gender; inclusion; student performance in LARS3; STEM teachers; S3 mathematics performance; school characteristics; teacher characteristics, beliefs and motivation; COVID-19 effects; pedagogy; continuous professional development; leaders in teaching.