Kelly Clarkson will be leading the voice cast of STX's 'Uglydolls' movie.

The 36-year-old singer has signed on to star in the animated feature based on the plush toy franchise and will provide speech for lead character Moxy.

'The Voice' judge will also perform original songs written for the film alongside Pitbull, who is also set to join the voice cast of the movie and will also provide original music.

The film, due for release in May 2019, tells the story of Kelly's character Moxy and her UglyDolls friends, who confront what it means to be different, struggle with their desire to be loved, and ultimately discover that you don't have to be perfect to be amazing because who you truly are is what matters most.

Speaking to Variety, Adam Fogelson - chairman of STX films - said: ''Kelly Clarkson has been a role model to millions of fans since the beginning of her momentous career. We look forward to collaborating with an artist of Kelly's exceptional talent and versatility.''

Kelly said: ''The UglyDolls' universal message celebrating our differences and individuality really resonates with me, and when STX showed me how incredible 'UglyDolls' will look and feel, I jumped at being part of that world. I can't wait to start working with the team at STX, the cast and filmmakers.''

This celebration of individuality comes after Kelly admitting that she wants to stay honest as a celebrity, as Hollywood can often be ''fake'' when it comes to physical appearance.

She said: ''[Full hair and make-up] is actual fake news. I think that sometimes Hollywood can be very 'Oh, we don't want people to see what we really look like. That'll be the death of you or something.' And it's like, 'Whatever!' Everybody poops. Everybody burps. Everybody's the same.''