She will voice the role of lioness Nala, next to lead character Simba, played by Donald Glover.
Beyonce used Facebook to confirm her long-rumoured involvement in the project.
Her other co-stars include Chiwetel Ejiofor as Scar and Seth Rogan as Pumba the warthog. James Earl Jones will play Mufasa, as he did in the 1994 original.
British comedian John Oliver has also been cast as Zazu, the hornbill voiced by Rowan Atkinson in the first film.
The film is being conceived along the same lines as another recent remake, The Jungle Book, which also saw big names voicing photorealistic computer-generated animals.
It is scheduled for release in July 2019 and will be directed by Jon Favreau, who also led The Jungle Book reboot.
In a statement, he said: “It is a director’s dream to assemble a talented team like this to bring this classic story to life.”