[Initial paragraphs] TESOL teacher education is, at its core, a set of practices that involve collaboration and interaction among individuals from various cultural, linguistic, and national backgrounds. It could be argued that its transnational aspect is a defining feature, which has become increasingly apparent in recent years. Transnationalism can be broadly understood as a process and practice of maintaining multiple connections between individuals and institutions that span nation-state borders (Vertovec, 2009). With English playing a pivotal role in mediating and shaping these connections, language educators have the responsibility to prepare students for participation in a globalized world with an awareness of its cultural and linguistic diversity. This raises a set of challenging questions about how transnationalism affects teacher knowledge formation, how teachers understand their work in the context of transnationalism, and what TESOL teacher education can do to prepare teachers for the challenges of transnational work. The book TESOL Teacher Education in a Transnational World: Turning Challenges into Innovative Prospects, edited by Osman Z. Barnawi and Anwar Ahmed, is a timely response to these questions. In addressing them, the editors bring together the diverse perspectives of scholars on the complexities of transnationalism in relation to teacher education.