The group, which is home to some of the country's most popular DJs, including Jamie Theakston, Harriet Scott, Nick Ferrari and Emma Bunton, is marking passing the million mark by launching updated versions of its apps, starting with 95.8 Capital FM.
The updated apps have improved audio quality and wider availability across platforms, and are being released for Android and Nokia mobile phones for the first time, including Google's new Nexus One phone.
The applications allow people to listen live to programmes on their phones. There is also a "slideshow" of content from the radio station available, with features such as "playing now" information, news headlines, competitions and offers.
Richard Park, Global Radio group executive director and director of broadcasting said: "Passing the million mark in application downloads is a great achievement for us, and demonstrates the increasing popularity of listening to radio 'on the go'."
Boosted by the acquisitions of Chrysalis Radio in July 2007 and GCap Media in June 2008, and led by chief executive Stephen Miron, Global Radio's portfolio of stations includes Heart, Capital, Choice, Galaxy, LBC and Xfm.