It was claimed yesterday that Simon and ITV had been impressed by Jessie's debut on The Voice at the weekend, and were hoping to poach her for the new series of The X Factor in the autumn.
The 23-year-old insisted today: "A lot of people were, like, 'Why aren't you doing Britain's Got Talent or The X Factor?'
"But I think it's really important in your career to pick things that really represent you as a person."
A source had told the Sunday Mirror yesterday: "She would be perfect for the X Factor.
"Simon could double her salary but he knows she isn’t only motivated by money. He can also give her the best possible platform to take her career to the next level."
But Jessie made it clear she'd be sticking with The Voice, for the time being at least.
"It's not about what the acts are wearing. Your look is not definitive," she explained. "It's very important to try to look your best. I love getting dressed up and making an effort. All that is part of it, but it's also about you doing it for the right reasons.
"It's about knowing, when you're a singer, that you can wear the greatest outfit but, if you're not breathing right or holding the mic right, you're not going to perform well and be seen as the voice — you're going to be seen as the clothes.
"The thing that made me agree to get involved with The Voice is that it's about the one thing I'm all about — the voice."
The Voice UK continues this Saturday on BBC One.