Chris Evans and Fearne Cotton are the hosts and there's performances from some of the biggest recording artists in the world.
As well as Gary himself, Robbie Williams, Barry Manilow, Dizzee Rascal, Ellie Goulding, The Wanted, Little Mix, Rizzle Kicks, Tom Odell and The Lumineers are just some of those who will rock the Hammersmith Apollo.
There's set to be some surprise guests and some appeal films too, to remind us it's all in aid of a very good cause.
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Children In Need Rocks, BBC1, 8pm