Over the last 10 years, radio listeners have increasingly begun to tune in online – via podcasts, radio-on-demand and other digital distribution platforms. In the last couple of years, they have begun to interact with radio in theatres, cinemas and assorted make-shift gig venues, via mobile apps and social media platforms, and in the form of live performances, online videos, maps, tweets, blogs, forums, essays, photographs and interactive websites. Radio, like every other medium, is experimenting with ever more complex cross-media practices. These kinds of activities have been analysed at length with regard to commercial film, television and gaming, but much less is understood about radio-born approaches to transmedia content. This article considers how existing transmedia theories can contribute to our understanding of these new radio practices and also how radio-originated cross-media productions might challenge some of the ingrained assumptions we have about transmedia engagement.