The announcement was made on Chris Moyles's BBC Radio 1 breakfast show on Tuesday morning. Moyles made his team play a guessing game, with the 'Price Tag' musician joining in answering 'yes' and 'no' questions in a variety of comedy voices.
Explaining the 'blind auditions' format to listeners, Jessie J confirmed that the UK format will have four coaches - who are both judges and mentors - and each will choose ten hopefuls after facing away from the acts while they perform.
The singer also praised the 'blind auditions', adding: "I do think sometimes that a lot of people don't audition for these shows because... they don't feel they look like a popstar. I can't wait, I'm so excited about it."
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Danny Cohen, controller of BBC One, said: "Jessie J is going to be an amazing coach on The Voice UK. She's a massive young star with a strong personality, and her recent MOBO nominations are testament to her musical and creative ability."
Jessie J added in a statement: "I'm excited to be a coach, inspiration and mentor and I jumped at the opportunity as it's all about 'the voice'."
Further coaches will be confirmed in due course. Musicians including Lenny Kravitz, Charlotte Church and Cheryl Cole have been linked to the programme.
The US version of the show - which is based on The Voice of Holland, an original Dutch format created by John de Mol - has performed well in the ratings. It will return for a second season on NBC immediately after the Super Bowl on February 5, 2012.
Coaches Christina Aguilera, Blake Shelton, Cee Lo Green and Adam Levine will all return for the US show's second season.
Anyone with the right to live or work in the UK may register to audition for The Voice UK by signing up via the show's website. Open auditions will begin in London on October 31 and continue across the UK throughout November.
The Voice UK premieres on BBC One in spring 2012.