The American duo will follow in the footsteps of Paris Hilton, who made a 50-minute appearance at the Mayfair venue in April.
Ronson is expected to join Sarah Harding's boyfriend Tom Crane on the decks during the evening.
Organiser Henry Conway is rumoured to be offering the pair more than the £70,000 paid to Hilton earlier this year.
"It's set to be madness outside with paps," a source told Metro. "The girls are the hottest property on the block so Sam will probably be able to command a hefty sum for her DJ slot."