There has been a boom in teacher motivation research in the last 15 years, in recognition of its potential significance for student motivation and learning outcomes, as well as for professional teacher recruitment and retention. Studies have examined motives for entering the profession, teachers’ orientations to their work, the sources of their motivation, and its consequences for themselves and for learners. In this chapter, we carry out a systematic review of research specifically on language teacher motivation in the period 2010–2020. We identified 43 articles or chapters that met our quality criteria, almost all of them related to English. An analysis of these showed a similar range of foci as in mainstream education but a strong predilection for qualitative research methodology. Taken as a whole, the research literature indicates that language teacher educators need to acknowledge the important role of motivation in shaping teachers’ work and careers, and to give it a more central place in pre- and in-service teacher development programs.