The celebrities, including fashion designer Stella McCartney, were among the mourners who gathered at London's St. Paul's Church for the hour-long funeral service to commemorate the life of the tragic star.
The designer, born Lee McQueen, was found hanged at his apartment in London on Feb. 11 and a post-mortem examination confirmed the 40-year-old died from asphyxiation.
He was laid to rest in a private ceremony on Thursday morning, when his coffin was covered in red, white and pink roses.
RELATED VIDEO: Alexander McQueen, a profile
A representative for McQueen's label reveals a public memorial will be held later this year, but company executives will not finalize details for the event until after Paris Fashion Week next month, when the couturier's latest collection will go on display.
The spokeswoman tells Women's Wear Daily, "We are focusing right now on the Paris show, which takes place on March 9."
GaGa paid tribute to her close friend McQueen at the recent BRIT Awards in London, where she put on a sombre performance in front of a huge statue of her wearing the late designers' bizarre Armadillo shoes.
RELATED: Check out our Fashion Week coverage