Guests at the West Hollywood party, held every year since 1993, attend on an invitation-only basis and tickets cost several thousand dollars, profits going to the singer's charity. The party includes a charity auction while guests watch the Oscars live on screens.
The Carters were at a table with comedian and former star of Home Improvement Tim Allen. Carter tweeted: "Tim Allen sitting at my table refusing to bid on Elton's piano in this amazing auction for Aids charity #wow".
There was no word on who invited the couple, but last year Carter attended an Elton John concert at Madison Square Garden in New York, making it backstage to tweet a photo of himself and Elton John, saying: "Not every day you get to meet a legend like this #eltonjohn #humbled".
Other stars at the party included Britney Spears, Heidi Klum and Kiwi actor Anna Paquin.