The news comes as Trainor releases new single Wave, while the Grammy-winning artist is set to release third album Treat Myself soon.
Trainor has previously judged on US TV talent show The Four: Battle For Stardom alongside Sean ‘Diddy’ Combs and DJ Khaled. The singer's biggest UK hit is 2014 chart-topper All About That Bass, which has 1,515,477 sales to date, according to the Official Charts Company.
Trainor said: “I am so excited and honoured to join Sir Tom, Will.I.Am and Olly Murs as the new coach on The Voice UK! It’s a dream come true and I can’t wait to sit in the chair with my own button and listen to some incredible new talent!”
Trainor replaces Jennifer Hudson, who is to star in an upcoming Cats film and Aretha Franklin biopic Respect, on the panel.
I can’t wait to sit in the chair with my own button and listen to some incredible new talent
Sir Tom Jones said: “I’m really looking forward to returning to The Voice, I just love doing this show. I’ve had a fantastic summer touring and performing songs I enjoy and have a passion for, so now it's time to discover some talented new singers to see what they can do!”
Will.I.Am added: “UK soloists, duos and trios – I am looking for you! This season I am seeking fresh sounds and unique voices that I want to work with and will compel me to push that button!”
Olly Murs said: “I’m so excited to come back to The Voice this year with a new energy and even a new knee – ready to defend my title as the winning coach. It’s fantastic to introduce a new Coach to the team as well and I look forward to getting to know Meghan.”
Presenter Emma Willis added: “I can’t wait for the next series of The Voice, especially to hear all of the incredible talent that will no doubt be walking onto that stage. I absolutely adore Jennifer and will massively miss her. However, Meghan is a fab choice to add to the coaching line-up and it's always exciting when a new coach arrives on the show.”
Katie Rawcliffe, head of entertainment, ITV said: “Meghan Trainor is such an exciting addition to The Voice UK. She has blown us away with her energy and enthusiasm and, although our youngest coach, an impressive career in music set to inspire all who join Team Meghan.
“We would also like to extend our heartfelt thanks, love and luck for the future to Jennifer Hudson. She has been a tremendous Coach, loved by viewers and the singers she has worked with during her time on the show.”
The show will begin filming next month and will air in 2020. This year’s winner was Brynn Cartelli.