The news about the two teaming up was given out by Lily Allen after Ronson cancelled a studio time with her because GaGa was in London, reported Aceshowbiz.
"I know that GaGa's here, 'cause I was meant to be in the studio with Mark Ronson tomorrow and he cancelled on me because GaGa's there," said Allen.
GaGa, 29, is currently working on her fifth solo album, which she has been referring to as "L5".
The record will be a follow-up to 2013's "ARTPOP" and GaGa is expected to reunite with RedOne, who was behind her most iconic hits like "Poker Face" and "Just Dance".