The singer told Digital Spy that her former Spice Girls bandmate is "the best person for the job".
The X Factor: Leona Lewis pleased about "feisty" Mel B news
Earlier today (June 11), it was confirmed that Mel B is joining Simon Cowell, Louis Walsh and Cheryl Cole on this year's panel.
Mel C said: "I'm really pleased Mel B is going to be the new X Factor judge. She is, without a doubt, the best person for the job - they don't call her Scary for nothing!"
The 'Feels So Good' singer previously appeared as a guest judge on the 2012 series. She has also judged on the Australian version of the show, as well as America's Got Talent.
'Gangnam Style' and saucy kisses: What we can expect from Mel B on X Factor
On joining the UK series, Mel B said: "I've always thought honesty is the best policy when being a judge and that's what I'm going to bring more of this year - whether it's spotting an incredible singer, giving someone a reality check or debating with Simon over who's got it wrong!
"Now I can't wait to get started and find some amazing talent."
The first filmed X Factor auditions this year will take place in Manchester on Monday (June 16), while the show will return to ITV later this year.