The film picked up the award for Best Motion Picture - Drama at the ceremony at the city's Beverly Hilton, while actor Rami Malek - who portrays frontman Freddie Mercury - got the nod for Best Performance By An Actor In A Motion Picture - Drama.
The band of the Grenadier Guards performed Queen's hit in front of Buckingham Palace just after 12pm on Monday.
The film has just won best film drama and best drama actor - Rami Malek as Freddie Mercury - at the Golden Globes. On Monday tourists walking by watched on and recorded the special moment, with one video getting over 67,000 views on Twitter.
Malek and producer Graham King, who accepted the film's Best Picture award, didn't mention Singer in their acceptance speeches, and any reference to the director appeared to be intentionally avoided by the rest of Bohemian Rhapsody's cast and crew throughout the Golden Globes.
Of course, such a surprise means Oscars predictions may look a little more different now.
The EE British Academy Film Awards will take place on February 10 at London's Royal Albert Hall.
"The mistake that critics made was reviewing the trailer instead of reviewing the film", May said while speaking backstage at the Golden Globes. Both Queen drummer Roger Taylor and guitarist Brian May attended the Golden Globes, and May spoke out on the negative reaction that the movie has received in some quarters. "This is for and because of you gorgeous", Malek concluded.
Bohemian Rhapsody's wins, however, raised questions for some viewers.
Indeed, Bohemian Rhapsody feels more like an obituary than a biography at some points, often dealing in half-truths rather than providing context to a man who was notoriously private.