The Humbug stars will be taught "hip-hop ways" by the rapper, according to The Mirror.
Helders said: "We speak to him at least three times a week. We are going to Miami in a few weeks and are going to be hanging out with him.
"He's going to be teaching us the hip-hop ways. He's a good mate, so it would be fun."
Diddy meanwhile wrote on his Twitter page: "Just kickin' it wit my boy Matt [Helders] from the Arctic Monkeys!
"I'm the newest member of the group! I'm signing him to Bad Boy [Diddy's record label]."
The 'Crying Lightning' group beat Kasabian and Muse to 'Best Live Band' at last week's NME Awards.