Keenan already oversees magazines, mobile TV, mobile, online and events and Emap said the move would allow for greater cross-promotional opportunities and accelerate its cross-media plans.
The group's radio stations include Kerrang!, Magic and the recently relaunched Kiss FM.
Dee Ford, Emap Radio's group managing director, will now report to Keenan along with other divisional MDs.
In June, Emap Radio's management came under fire from Ofcom, which accused the group of "abject failure" in managing its talent responsibly after items featuring strong language and prank calls on Kiss FM's Bam Bam breakfast show attracted 10 complaints and the regulator's biggest ever radio fine of £175,000.
Emap also announced today that Derek Carter, chief executive of Emap Communications, the group's business-to-business division, was joining its board.
Emap adds radio to Keenan's remit
Emap has restructured its radio division, bringing it under the remit of Paul Keenan, chief executive of Emap Consumer Media.