Executive producer Simon Cowell wants to land the hip-hop beauty - famed for her wacky outfits and curves - and met with her in Los Angeles earlier this month.
A source told a US newspaper: 'Simon thinks Nicki is fantastic. She's sassy, she looks great and has bags of personality. She has a large following and fits well with the ethos of the show, which plans to usher in a new generation of musical talent.
'This isn't a done deal yet, but Nicki would be great for the show. She fits the ideal that X Factor will be exciting, vibrant and different. And the show would also be great for her career.'
Former Island Def Jam Music Group chairman L.A. Reid is so far the only confirmed judge on the show, which will debut on the Fox television network this autumn.