This year's new series sees Sir Tom join Anne-Marie, Will.i.am and Olly Murs in the spinning red chairs.
Saturday evening saw the blind auditions return for the brand new season.
During a break between auditions, Sir Tom belted out a cover of Cry to Me by Solomon Burke from his chair, joined by The Voice's resident band.
Watch Sir Tom Jones's performance on The Voice UK 2021 below...
Anne-Marie reacted: "Wow I can't believe that voice comes out of your mouth.
"I can't believe that's right in my earhole. That I'm actually experiencing that is so, so great."
"Well thank you," responded Sir Tom.
Auditioning acts acts on this weekend's episode included 21-year-old Esther Cole who joined Tom's Team after singing Let Me Down Slowly.
Meanwhile 26-year-old full-time musician Leona Jorgensen from Sheffield performed Post Malone & Swae Lee's Sunflower for her blind audition, winning a spot on Team Anne-Marie.
Once more hosted by Emma Willis, this year's series of The Voice is open to soloist, duos and trios.
At stake is the top prize of a recording contract.
The public will vote for the winner of The Voice in a final later this year.
The Voice UK 2021 is broadcast Saturday evenings on ITV.
You can watch and stream full episodes of The Voice UK 2021 on the internet via the ITV Hub website.
Acts who make it past the audition stages will go on to take part in the battle rounds later in the series.