Book excerpt: The rise of global mobility has had a deep impact on the study of urban multilingualism. Once associated with research on minority speech communities and inner-city ethnolinguistic enclaves (Chinatowns, Little Italies, etc), it is now concerned much more with the use of multiple languages in diverse neighbourhoods across the city. In this book the authors take an innovative approach that builds on previously published work in two ways. First, it focuses on a single city and, second, it adopts a multidisciplinary approach to multilingualism. By examining the phenomenon of multilingualism in a single city from a range of perspectives this book paints a more comprehensive picture of the current dimensions of urban multilingualism. A unique feature of this book is the inclusion of contributions from scholars with expertise in education, geography, media, health communication and international studies, in addition to community practitioners. Sydney is the largest city in Australia and, on most counts, it is also among the most linguistically diverse cities in the world. As such it is an ideal site for a multidisciplinary study of urban multilingualism. The selection of 18 multidisciplinary case studies on multilingualism in Sydney, Australia represents some of the strongest and most innovative research on urban multilingualism in the world today. This book examines how multilingualism permeates institutional and everyday practice in the city, raising important questions about what a ‘multilingual city’ can and should be.