The "Honey Bee" hitmaker, who was crowned People magazine's 2017 Sexiest Man Alive, will voice the role of Ox, the unofficial mayor of a fictional town called Uglyville.
The gig also features Blake performing original songs as the cocky character.
"Blake is one of country music's most talented and highly regarded artists, and his signature wit and infectious charisma lend themselves perfectly to the character of Ox, who fancies himself a defacto Mayor of the "UglyDolls", Adam Fogelson, chairman of STXfilms, shares in a statement to Variety.
Blake's "The Voice" co-star Kelly will lead the cast as Moxy, who, along with her pals, confront issues about fitting in as they learn to eventually love themselves.
Clarkson, Jonas, and Pitbull will also contribute new material for the movie soundtrack.
The children's project, designed to be the start of a film franchise, is due to launch in theatres in May, 2019.
Blake is gradually building up his acting resume - he previously made an appearance in "Pitch Perfect 2" and Adam Sandler comedy "The Ridiculous 6" as famed gunslinger Wyatt Earp, while he also voiced Earl Pig in another animated film, 2016's The Angry Birds Movie.