The singer-turned-actor sported an off-the-shoulder, puffy-sleeved couture frock by Valentino to walk the red carpet at the Beverly Hilton, without her usual peroxide ‘do.

Gaga, 32, won Best Original Song for Shallow from the movie, A Star is Born, but in a huge upset, lost to Glenn Close in the Best Actress - Drama category.

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On the red carpet, Gaga’s choice of blue was said to be a subtle nod to Judy Garland, who starred in the 1954 version of A Star is Born and wore the icy hue on-screen.

Vogue Australia senior fashion features editor Alice Birrell said Gaga’s gown was “fashion as fantasy exemplified” and would now be a defining style moment for her.

“That idiosyncratic shade of blue (the conversation in the Vogue office right now — ‘is it Periwinkle? Powder blue? A touch of smoky sky?’) that entrances … and the matching hair ice blue hair that could only work on her,” Birrell said.

“In 2019 no one is naive enough to think that a star is born in a single moment, but with this dress, Gaga’s will likely be immortalised.”

The Golden Globes marked the start of Hollywood’s awards season for 2019. After a record $US41.7 billion global movie box-office in 2018, crowd-pleasers like A Star is Born, Black Panther, Bohemian Rhapsody and Mary Poppins Returns competed for top honours.