A language teacher’s work is never really done. From entering a teacher education program for initial qualifications onwards, language teachers must always be on the lookout for new approaches, methods and insights into their teaching and development. This need for ongoing professional development is not a reflection of any inadequate initial teacher education or training deficits, but rather a reflection that the knowledge base of language teaching is constantly expanding, and the world changing (e.g., we are in the midst of the COVID-19 pandemic that has pushed us all to quickly pivot to online platforms for teaching and development), and we must try to keep up with our own development. Insights into Professional Development in Language Teaching is about how we can continue with our professional development as language teachers and examines a variety of approaches (individual and collaborative) to professional development for language teachers. The book is intended as a practical introduction for language teachers, and guide for administrators and other stakeholders, who wish to implement a coherent and strategic approach to language teacher development.