Fans of the Born This Way musician broke the news using a large black and white banner at an event in Times Square on Thursday evening.
Speaking to MTV News, GaGa said: "I have a really big announcement, but I thought as usual, instead of me announcing it, I'd let the Little Monsters do it for me."
On opening the ceremony, she said: "It means the world to me. I just feel really blessed every day. I have the most amazing fans."
GaGa will launch the telecast on Sunday, August 28 from the Nokia Theatre in Los Angeles. She is nominated in four categories at this year's MTV Video Music Awards - 'Best Art Direction' and 'Best Choreography' for 'Judas', plus 'Best Female Video' and 'Best Video With A Message' for 'Born This Way'.
Katy Perry leads the nominations with recognition in ten categories, including 'Best Video With A Message'.
The MTV Video Music Awards 2011 air live from the Nokia Theatre in Los Angeles on Sunday, August 28 at 9pm ET/PT.
> Lady GaGa plays piano, removes bra in MTV VMAs video
Watch the video to 'Born this Way' by Lady GaGa below: