Beyoncé was invited along with rapper husband Jay Z and their daughter Blue Ivy to Michelle's star-studded private party held in Washington DC on Saturday (18 January).
Beyoncé, who also performed at the event, shared some photos of the day with fans on her Tumblr account.
The 32-year-old 'Crazy In Love' singer also made friends with the family dog Bo, and was seen stroking the pet as she sat in a chair.
The Carter family looked smart for the grand occasion and while Beyoncé wowed in a gold mini-dress and nude heels, Blue added the cute factor in a white dress with a tulle skirt.
In another photo, the trio are pictured making their way towards the building as little Blue clutches onto her mother's hand.
Beyoncé performed a special set for Michelle including her chart-topping hits, 'Single Ladies' and 'Irreplaceable'.
Joining Jay and Beyoncé was John Legend, Jennifer Hudson, Mary J. Blige, Stevie Wonder and Samuel L. Jackson.
President Barack Obama, who also gave a speech at the party, sent out a birthday tweet to wife Michelle. He said: "Happy birthday, @FLOTUS. Thank you for all that you do."
Meanwhile, Michelle joked: "Excited to join Barack in the 50+ club today."
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Watch Beyoncé's video for 'Drunk In Love' below: