Anne-Marie joins Tom Jones, Olly Murs and Will.i.am in the famous red chairs for the 10th series of the talent show.
US pop star Meghan Trainor stepped down from the show after one series after announcing she is expecting her first child with husband Daryl Sabara.
Anne-Marie said: "I am SO excited to join Sir Tom, will.i.am and Olly as the new coach on The Voice UK. I can't wait to work with incredible undiscovered talent! Wahoooooo!"
The show will return to ITV next year with the introduction of a new format called The Block.
During the blind auditions, the four coaches will each have the opportunity to stop a fellow coach from adding a singer to his or her team.
Each coach will get only one chance to use their "block" in the hope of trying to secure the best team possible.
The winner of the show will secure a recording contract with Universal's label UMOD.
Jones said: "I am really looking forward to working with Anne-Marie for the upcoming series of The Voice UK. Anne-Marie will bring an injection of fresh energy and ideas which is fantastic. I'm excited and anticipating a fun and challenging new Series 10!"
Will.i.am added: "I'm really excited about this new season and welcoming Anne-Marie as our newest coach on The Voice UK. With her songwriting, singing and performance skills, plus her tell-it-like-it-is approach, this makes her the perfect mix-it-up addition to this season."
Murs was joined by Anne-Marie as a guest mentor during the 2019 series, and he said: "The advice and help she gave to my contestants that day was invaluable. I'm a huge champion of her.
"I can't wait to hear about her own journey and I'm sure she will be a fantastic coach. She is one of the biggest female artists in the industry right now, so it's great to have her join the team and also help bring the Essex ratio up! We are taking over!"
Trainor announced her pregnancy on October 7, sharing a picture of her ultrasound on social media and writing: "You all know how long I've wanted this!!!!
"@darylsabara and I are so beyond happy and excited to meet this little cutie early next year! WE'RE PREGNANTTTTT!!"