The pair beamed as they walked the red carpet in London’s Leicester Square, ahead of its first official British screening.
Gaga tried out some Shakespeare chic for the occasion, sporting a ruff with her bejewelled couture dress, looking a million miles away from the up and coming musician she plays in the film.
‘A Star Is Born’ is a remake of the classic film first made famous by Janet Gaynor in 1937, with subsequent versions starring Judy Garland and Barbara Streisand.
It tells the story of unknown singer-songwriter Ally (Gaga), who is discovered by country rock star Jackson Maine (Cooper) and the pair subsequently fall in love.
It has already generated huge Oscars buzz, despite it being Gaga’s first film role and Bradley’s directorial debut.
The premiere came as the film’s lead song ‘Shallow’ was released online.
The track has already become a huge favourite to bag the Best Original Song accolade at next year’s Oscars, and shot up the iTunes charts across the globe just moments after its unveiling.
At the premiere, Gaga told reporters how she revisited her experiences of being bullied as a schoolgirl to prepare her for her role.
“When I first decided I was going to go for it in the music industry I just believed in myself so much and I was pounding down every door to get a meeting or to get a slot to play at a dive bar,” she said. “But Ally is very different, she doesn’t believe that she’s beautiful, she doesn’t think that she has anything to say that anyone wants to hear, that she will never make it.
“So I actually went back further to high school when I was bullied and I didn’t believe in myself, that’s the major difference.”
Responding to the Oscar buzz around the film, Bradley added: “I’m elated that I’m hearing that, but at the same time if there is one thing I’ve learned in this business is people say a lot of things early on and we haven’t even opened the movie yet so my hope is people come to see the movie.”
‘A Star Is Born’ is released on 5 October.