The starting point of this chapter is the question of how mathematical modelling can be promoted in teacher education from different perspectives. A review of the existing literature on teacher education within the ICTMA community presents the development of studies over the last 20 years, from smaller qualitative studies to larger studies and studies on in-service teachers. The theoretical findings on teachers’ professional competence in mathematical modelling are discussed and empirical results are reported. A study investigating a teaching approach that combines theoretical and practical work in a teaching–learning lab to effectively teach professional competence is reported. Furthermore, the impact of technology on teachers’ professional competence in mathematical modelling is discussed. In this context, the approach is extended to modelling with technology and first empirical results are reported.