The singer will make his movie debut opposite Jennifer Hudson, Taylor Swift, Idris Elba, Dame Judi Dench, and Sir Ian McKellen in the project, which starts shooting next month, according to Billboard.
Rebel Wilson also recently joined the cast - as lazy puss Jennyanydots.
The film will be a faithful adaptation of Andrew Lloyd Webber's stage musical, which was inspired by poet T.S. Eliot's Old Possum's Book of Practical Cats.
Hudson is playing Grizabella, Elba will tackle Macavity and McKellen is Gus the Theatre Cat.
Meanwhile, Dame Judi will play a female Deuteronomy in the movie version after originally booking the role of Grizabella in the original West End production in 1981.
An injury forced her to pass on the role and withdraw from the show, leaving Elaine Paige to take the part and become synonymous with the production.
Dench's new role has traditionally been played by men - Brian Blessed originated Old Deuteronomy in the London musical and the part has also been played on stage by Ken Page, Jeff Leyton, and Quentin Earl Darrington.
Lloyd Webber previously revealed Taylor Swift had signed on in July, explaining she will play either flirty Bombalurina or the skittish Demeter.
Lloyd Webber has penned a new song for the film and will serve as an executive producer.
Hooper's "Cats" will hit cinemas in December, 2019.