President Obama: The Belieber in Chief!

Justin Beiber serenades first family alongside such performers as Jennifer Hudson, Cee Lo Green and The Band Perry at annual event in Washington to benefit the Children's National Medical Center

Who knew President Barack Obama had a base case of Bieber Fever?

Sure enough, the commander in chief gave us a glimpse of his inner teenybopper as he grooved to Justin Bieber during the Christmas in Washington concert at the National Building Museum on Sunday.

The annual event, which also featured performances by Cee Lo Green, Jennifer Hudson and The Band Perry, was hosted by Conan O'Brien, who told the crowd that the holidays serve as a reminder of the miracle child worshiped by millions.

"I'm speaking of course, of Justin Bieber," joked the talk show host as he introduced the heartthrob, who took the stage to sing "Mistletoe" and  "Away in a Manger."

In addition to the president, the show was also attended by his wife, Michelle, and the couple's two daughters, Sasha and Malia. During the concert, O'Brien playfully took a swipe at the first lady's "Let's Move" health campaign.

"It's not easy to be a child at the White House these days," he pointed out. "Santa's probably not going to stop at a house that leaves out a cup of organic soy milk and a plate of celery cookies."

Prior to the big show, which benefited the Children's National Medical Center, the Obamas met with several of the hospital's young patients, who were dressed as elves.

The concert is scheduled to air this Friday on TNT.