The Up in the Air star was joined by 150 celebrities including Robert Downey Jr, Barbra Streisand, Salma Hayek and Tobey Maguire at a lavish dinner party at his secluded home in Los Angeles.
Guest of honour Obama arrived with 30 Secret Servicemen. Dinner by Wolfgang Puck was served on the basketball court of Clooney's sprawling estate.
The gala, which was announced last month to raise money in the campaign for Obama's re-election, was $40,000 (£24,800) per person.
Clooney was able to raise around $15 million (£9.3 million) in celebrity donations, according to The Daily Telegraph.
Obama said in his thank you speech: "I want to thank Clooney for letting us use his basketball court. We raised a lot of money because everybody loves George. They like me, they love him. And rightfully so. He seems to occupy a constant state of grace, and uses his extraordinary talents on behalf of something truly important."
Glee creator Ryan Murphy will also host a fundraiser dinner for Obama with his partner David Miller, with tickets currently set at $40,000 (£24,800) per couple or $25,000 (£15,500) per person.