This chapter considers the role played by radio in popularizing and defining country music. Radio as a format pursued a commercially driven mediation of identity that worked against applying an artistically driven musical genre definition. In particular, these debates revolved around gendered presentation and women as listeners and performers. From the 1920s through World War II, radio’s prominence in country turned on live radio shows as the media introduction of southern whites. A second era, from the end of the war to mid-1970s, saw a shift to disc jockeys and records: personality radio. Format radio country, a tighter programming approach, solidified from the mid-1970s to the mega mergers of the late 1990s. Most recently, in an era of Internet access and new business models for music, country has confronted the less sympathetic position of networked radio.