Research on teacher competence and teacher expertise has remained unintegrated in recent decades, despite the two paradigms having common roots—a focus on teachers’ knowledge, its significance for successful teaching, and expectations of teacher professionalization. In this survey paper, we identify the differences and commonalities between the two paradigms based on long-term work in the fields and high-standard handbooks; and we explore the possibilities of integrating and developing them further to underpin evidence-based theory development for the teaching profession. First, we describe the development of the teacher competence paradigm, which has strongly influenced the discourse on the professionalization of teachers in general and mathematics teachers in particular. The first conceptualizations of teacher competence focused mainly on cognition, affect, and motivation. Further developments integrated a situated perspective on teacher competence including teachers’ noticing as situation-specific skills to better align with teachers’ actual performance. Thereafter, we unfold the different perspectives developed within the general expertise paradigm, followed by specific approaches focusing teachers. Finally, we reflect on the characteristics of the two paradigms, namely the focus on dispositions of the competence paradigm or on performance as outstanding pedagogic practices of the expertise paradigm and on ways how to integrate them. We close the paper with first ideas for a research program integrating both paradigms by proposing a heuristic of teacher expertise including a competence-oriented perspective.