Innovation in education is crucial for promoting improvement and sustainable development in schools. Innovation can lead to changes in structure and functioning, is closely linked to experimentation and the search for new approaches and ideas for educating children, and is ultimately implemented at the classroom level. Widespread innovation in schools is primarily driven by educational leadership, which affects the conditions under which teaching takes place, as well as the teaching itself, and has an impact on student achievement. Although leadership and innovation in schools are receiving increasing attention, there is a lack of systematic reviews and meta-analyses that systematically and transparently synthesise the relationship between these two issues and the underlying assumptions that would enable evidence-based decision making. In addition, research on educational innovation is rarely linked to mainstream innovation research, making the measurement of innovation in education a pioneering endeavour. Against this background, this project aims to systematically review the state of knowledge on this topic and to produce robust findings based on meta-analytic methods. The project will carry out three types of analyses: 1. systematic reviews, 2. traditional meta-analyses, 3. meta-analytic structural equation modelling. The latter will use data from international large-scale evaluation studies.