Teacher autonomy has been a topic of growing interest over recent decades. However, what teacher autonomy means remains work in progress. Drawing from existing conceptualisations, which consider teacher autonomy as a multidimensional and context-dependent phenomenon this paper presents an analytical device applicable in international comparative studies. The conceptualisation is presented in the form of a matrix, which distinguishes different domains and levels of teacher autonomy. A sample of existing research is then utilised to demonstrate how the matrix can assist in cumulative knowledge building. The article demonstrates how the matrix can be applied, in particular, to empirical comparative research.