This introductory chapter lays out the basic concerns and background of the book, making a case for the need for alternative understandings of applied linguistics, and the importance of the contribution of the Global South to Global North scholarship. Looking at applied linguistics from a southern perspective is not just a case of adding some perspectives from the South, or including various southern people who are often forgotten, or incorporating geographical areas or topics occluded from analysis in Global Northern applied linguistics. The Global South presents a much more far-reaching set of challenges to what applied linguistics means, what it encompasses, what its central concerns are, what it regards as its antecedents and historical pedigree, and what ideas and traditions it therefore draws on. The innovations and challenges we want to bring to applied linguistics in this book extend far beyond an agenda that seeks to redress various exclusions; rather, these are deep-seated challenges to some of the core tenets of applied linguistics as well as new directions for theories and practices in the field. For applied linguistics, the questions raised by southern perspectives address not only its colonial past and contemporary location in neo-liberal times, but also its key tenets about language, knowledge, and education. In this chapter, we consider some of the tensions around the Global South framework, before outlining both some of the useful questions this perspective can open up as well as some of the challenges this poses for applied linguistics.