Kelly Clarkson wears floral gown to Inaugural Ball (Photos, Poll)

Kelly Clarkson sported a romantic, floral look at the Inaugural Ball honoring President Barack Obama on January 21.

The Grammy-winning pop star and first winner of "American Idol" attended the event with her fiance, Brandon Blackstock. She wore a strapless, sweetheart neck Oscar de la Renta gown printed with a dazzling array of white, yellow and reddish orange flowers and green leaves and posted on her Twitter page two photos of herself.

"My dress barely fit in the car for tonight's festivities. I feel like Cinderella! Thank you Oscar De La Renta!" she Tweeted.

(Check out photos of Kelly Clarkson, Alicia Keys, Jennifer Hudson and other celebrities, as well as President Barack Obama and First Lady Michelle Obama, who stunned viewers with a bright red Jason Wu gown.)

Clarkson later Tweeted: "Just partied at the White House ....I kid you not, Michelle Obama stood up and got the party started ....seriously cool First Lady :)."

The singer had earlier in the day performed "My Country, 'Tis of Thee" at the Presidential Inauguration ceremony (watch video, below).

"Wow ....I was incredibly nervous and cold ha!" Clarkson said on Twitter after she sang. "I just wanna officially thank President Obama for opening for me haha! Just kidding :)"

Beyonce, a longtime supporter of Obama, also sang at the event -- she performed the national anthem (watch video). Clarkson later posted a photo of herself with the singer, Tweeting: "Me and B just hangin' out ....don't worry about it. Seriously, God did good. She is so beautiful!"

Other stars who attended the Inauguration ceremony included actresses Eva Longoria and Kerry Washington. Check out photos.

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