The band have allegedly been booked for the Wembley Arena-based show next month and insiders have suggested that they are keen to sing with Janet Devlin.
The show's bosses are hoping Devlin will make the final so she can sing her rendition of 'Fix You' with the group, who have been hailed as one of the world's biggest bands.
A source told the Daily Star: "There isn't anyone left in the show who would suit Coldplay's music apart from Janet.
"She wowed everyone when she sang 'Fix You'. It shows how confident everyone is that Janet will make the final."
According to the tabloid, Michael Buble is already booked to perform for the two-part final on December 10 and 11 and is touted to sing with Marcus Collins, as insiders think the pair's "old-style" vocals would blend well.
A third guest has yet to be booked, but girlband Little Mix are hoping Jessie J will perform with them if they reach the final stages of the competition.
Member Jesy Nelson said: "It would be so cool to duet with her in the final if we make it."
Last month, Coldplay stated that they would never appear on The X Factor as they are "far too old".
Meanwhile, this weekend's quarter-final stages of the singing show will have a Guilty Pleasures and Heroes theme.
Watch Janet Devlin perform Coldplay's 'Fix You' below: