Over the last 50 years, the ultras have become the most widespread, outspoken and spectacular form of football fandom across the globe. Whilst the ultras phenomenon began in Italy, then spread across Southern Europe into Northern Europe, it is now the dominant style of fandom in North Africa, South East Asia and East Asia and is spreading into North America and Australia. This spectacular style of fandom has been spread through global media, social media and increased travel, where fans can view, engage and interact with a range of fans from across the globe and bring various local dimensions to their fandom. This volume brings together a range of articles about the ultras' style of football fandom. It is designed to be an introduction: a first account of ultras for the uninitiated. What follows are analyses and accounts of ultras in Italy, France, Germany, Poland, Turkey, Israel, North America, Australia, Indonesia and Croatia. Not only does this volume demonstrate the prevalence of the ultras' style of fandom across the globe, it shows how football becomes an important cultural arena to see the intersections of globalization and localism. This book was originally published as a special issue of Sport in Society.