The Hollywood star, known for leading roles in Lord of the Rings, and Pirates of the Caribbean, follows other famous faces to appear on Bedtime Stories such as Tom Hardy, Sir Elton John and Dolly Parton.
Ewan McGregor, actor Chris Evans, George Ezra, Suranne Jones, Dame Jessica Ennis-Hill and Eddie Redmayne have also all taken part in previous episodes.
Bloom, 41, will be reading from We Are Together, written and illustrated by Britta Teckentrup, on 9 November. It is the first of two stories recorded with the actor.
“Through my travels as a Unicef Goodwill Ambassador, I've met children in countries all over the world, and witnessed firsthand how storytelling between adults and young children helps cement their bond," Bloom said in a statement.
“Children light up when being taken on imaginary adventures through storytelling, and it helps their creativity grow. It was great to be a part of CBeebies Bedtime Stories.”