Leary is the star of the firefighter drama series "Rescue Me."
Chris Cornell, One Republic, Pussycat Dolls, Solange Knowles and Timbaland with special guest Lynyrd Skynyrd have been added to the lineup of performers for the 5th annual event to air on CBS Sept. 9, the network said.
The show will also feature appearances by the previously announced artists Beyonce, Black Eyed Peas, Chris Brown, Kid Rock, Duffy, Fergie, Justin Timberlake, Lil Wayne, Keith Urban, Mariah Carey and Rihanna.
'Happy' fan videos make Pharrell cry [VIDEO]
Pistorius testifies he didn't consciously pull trigger when he shot girlfriend