Here, the Welsh legend gives his views on his final five ahead of tonight's show, where the public will decide who stays and who goes.
On [tag]Matt and Sueleen Fletcher[/tag]: "I thought they were brilliant. I love their harmony - they complement one another."
He added: "The harmonies are really, really good. It's fantastic."
On [tag]Sam Buttery[/tag], Sir Tom revealed to the Radio Times: “There were a few notes in there that I bought sounded like me - sounded like me in my head anyway! I think he's got a great voice.”
On [tag]Leanne Mitchell[/tag], Sir Tom says: “I listened to the tone of her voice and I liked the lower register. When she started, I thought she had a lot of timbre in her voice - very appealing for me.
On [tag]Ruth Brown[/tag]: “She's a great singer and that's why hit the button. I really wanted her on my team.”
On [tag]Adam Isaac[/tag]: “I've sung with a lot of people and a lot of different kinds of songs - I needed somebody with a strong voice who can sing and play like that.”
Tonight all five of the singers will be performing, with one leaving in tomorrow night's results show.
See all the action from 7PM on BBC One tonight.
Browse The Voice UK contestants below...