The 'OMG' singer uploaded pictures of the event on Instagram, which showed him and his friends break dancing, laughing and a boxing ring-themed cake with a baby photo of the singer in the middle, reported E! online.
Many celebrities also took to Twitter to wish the singer.
"Happy birthday, Usher! He is one of the most talented musicians and performers I've ever met," celebrity talk show host Ellen DeGeneres tweeted.
Usher's 'The Voice' co-judge Shakira wrote, "Dear Usher, a great colleague, an exemplary artist and human being! Happy birthday and many blessings for you today and always.