This richly illustrated book is the first dedicated to volcanism on Io. It describes and explains the different styles and scales of volcanic activity on this fascinating moon, and compares Io's diverse volcanoes with their contemporaries on Earth. It also provides background as to why Io and Earth are volcanically active, and describes how remote-sensing data from spacecraft and telescopes are analyzed to reveal the underlying volcanic processes. Containing the latest results from the Galileo mission, this book is a fascinating reference for advanced undergraduates, graduate students and researchers in planetary science, volcanology, remote-sensing and geology.