The 32-year-old singer and actress told The New York Times that she had slept in, and had no idea about the nominations until 8.30am (PST), three hours after the announcement, when she received a call from her manager Bobby Campbell.
"I've been trying to get some sleep because I'm on showbiz time," she explained. "I woke up around 8:30 and I didn't know anything about it. (When I heard the news I) just burst into tears."
GaGa also slept through all of the congratulatory calls and text messages she received after the nominations were announced.
"A Star is Born" received eight nominations for the Oscars, including for Best Picture. And while GaGa's co-star Bradley Cooper was nominated in the Best Actor category, he was notably snubbed for Best Director - the film is his directorial debut.
Speaking about the snub, GaGa told The Los Angeles Times: "Well, you know, you never know what's going to happen. But at the end of the day, he knows that he's the best director in my eyes, and in all of our eyes as his cast. I know that he's so happy that we've all been nominated and that the film was recognised and we all feel really, really beyond elated for the recognition."
Meanwhile, Bradley issued a statement expressing his gratitude for the nominations the movie did receive.
"Everyone who worked on this film truly risked putting themselves out there - in the hope that in doing so people will connect and feel something deep and personal - the way films have made me feel since I was a kid," he said. "When I got this opportunity I knew I had to risk it all because I may never get another chance - so to be here today in a place where people who have seen the film are talking about how it makes them feel, something deep - that simple human thing - that we need each other - and the Academy to recognise that this morning - I just am so grateful."