The teenager from Belfast will be seen in tomorrow night's opening episode trying to win over the panel of coaches with her voice.
The 17-year-old performs an acoustic cover of Jessie J's - one of the show's coaches - Price Tag, singing with her guitar.
She said: “It was such a brilliant experience. I feel so grateful to have been allowed to take part.”
And without giving away which of the coaches she chose to team up with, Jessica hinted: “I love each of them but Jessie J has something special - I love the messages in her songs.”
The Voice UK starts on BBC One on tomorrow night at 7pm.