The 'Back To Black' singer was found dead in her Camden home yesterday afternoon. Her death is being treated as "unexplained" until an autopsy can be performed next week.
Joining the wealth of stars that have already paid tribute to the 27-year-old, GaGa credited Winehouse with giving her "hope" that an aspiring singer with jazz roots could achieve mainstream success.
"Amy changed pop music forever," she wrote on Twitter. "I remember knowing there was hope, and feeling not alone because of her. She lived jazz, she lived the blues."
GaGa has previously opened up about her fascination with Winehouse, saying: "Amy is a real artist... I watch performances from Amy where I swear she didn't hit a note, and she was shot and shot deep on something, but I can't take my eyes off that beautiful girl. There's something about her that's so honest."
The 'Edge Of Glory' singer further commented in 2009 that Winehouse paved the way for her own success.
"I will always have a very deep love for Amy Winehouse," she said. " I don't believe that what I do is very digestible, and somehow Amy was the flu for pop music.
"Everybody got a little bit of the flu and got over it, and fell in love with Amy Winehouse. And now, when more flu comes along, it's not so unbearable."
Other celebrities to have paid tribute to Winehouse include her "musical soulmate" Mark Ronson and Russell Brand, who described her as a "f**king genius".
> Amy Winehouse family: 'We've been left bereft'
> Amy Winehouse mourned in Camden
> Obituary: Amy Winehouse
> Amy Winehouse 1983-2011: A life in pictures
> Amy Winehouse death: Reactions so far
> Amy Winehouse: Career highlights in pictures
Listen to a YouTube mash-up of Lady GaGa's 'Just Dance' and Amy Winehouse's 'Tears Dry On Their Own' below (from user kavalheiru):