The musician says he'll be duetting with a "very talented artist".
It's not clear if he will be teaming up with one of the acts as part of the traditional finalist duets, or joining one of the guest stars due to appear.
Little Mix, Sam Smith, Pink, Louis Tomlinson and more have been confirmed to sing over the weekend.
Tokio, who released debut album Our Generation last month, teased: "Tune in tonight! I will be duetting with a very talented artist! 👊 #xfactor"
As yet no confirmed details about the X Factor 2017 final duets has been announced.
However the acts themselves have revealed their hopes.
Boy group Rak-Su have said they'd love to team up with Craig David, while Kevin Davy White said: "I have three in mind. Will.i.a,am, Gary Clark Jr - he’s an American singer - or Alicia Keys."
The pair's fellow finalist Grace Davies has said she wants to duet with Robbie Williams in The X Factor 2017 final.
Grace revealed she was a massive fan of the ex Take That singer and hoped they could duet on his 2002 song Feel.
"That's my jam," she told the tabloid.
The X Factor 2017 airs LIVE on ITV tonight at 7:05PM with the latest live performances.
The final continues Sunday at the slightly later time of 7:20PM.
As well as the songs from the acts, the final weekend will see a number of guest performers with Little Mix, Pink, Pretty Much, Louis Tomlinson and Sam Smith all confirmed to perform.