The concert will be held on 7 June at London's Emirates Stadium. The radio station hopes to attract listeners who also attended the Jingle Bell Ball at the O2 last December.
Fourteen music acts will perform at the Summertime Ball in front of a predicted audience of 55,000. 95.8 Capital FM will broadcast live from the venue from 10am - 10pm.
The event is supporting Capital's flagship charity, Help a London Child, with a donation of £100,000 to be made from the proceeds of the event.
Details of the featured artists will be announced soon.