About 150 supporters are to attend the May 10 event at Clooney's home in Los Angeles. Tickets are $40,000 each, with proceeds going to the Obama Victory fund, a joint fundraising committee of Obama for America, the Democratic National Committee and several state Democratic parties.
"I'm proud to do whatever I can to support the president ... as long as no one asks me to sing," Clooney told the entertainment news program.
Clooney is a film star and director known for his humanitarian work. Katzenberg is one of the founders of DreamWorks movie studio.