This book offers a self-reflective, critical approach to the study of what is popularly known as polyglossia, charting the gradual but marked process of its commoditization over the last 20 years and offering a counterpoint to mainstream positivist treatment of serial language learning. First, from a diagnostic standpoint, the book examines the rise and consolidation of the Polyglot Community in the sociopolitical and economic context of its gradual transformation into and partial overlap with the Polyglot Industry and its ideological tenets (the Polyglot Matrix). Second, from a prognostic standpoint, the book posits Critical Polyglot Studies (CPS) as a much-needed counter to the many theoretical and practical shortcomings of the Polyglot Industry-cum-Matrix, presenting the main programmatic points and illustrative best practices and institutional case studies of this alternative paradigm. CPS is conceived as both a research orientation and as a strategic attempt to elicit debate and draw in a wider range of polyglossia scholars, offering readers with actionable tools to contribute to this emerging academic and activist endeavor. Constituting the first critical and systematic analysis of polyglossia as a globalized phenomenon, this book will be of interest to scholars of linguistics, cultural studies, critical theory, and sociology.