A century ago, the emergence of radio, along with organized systems of broadcasting, sparked a global fascination with the 'wonder' of sound transmission and reception. The thrilling experience of tuning in to the live sounds of this new medium prompted strong affective responses in its listeners. This book introduces a new concept of radiophilia, defined as the attachment to, or even a love of radio. Treating radiophilia as a dynamic cultural phenomenon, it unpacks the various pleasures associated with radio and its sounds, the desire to discover and learn new things via radio, and efforts to record, re-experience, and share radio. Surveying 100 years of radio from early wireless through to digital audio formats like podcasting, the book engages in debates about fandom, audience participation, listening experience, material culture, and how media relate to affect and emotions.