Angelina Jolie has signed on to provide the voice of Stella in Disney's long-gestating adaptation The One and Only Ivan, becoming the first voice cast member to come aboard. The actress was already attached to produce this adaptation, alongside Allison Shearmur, who has helped produce Disney hits such as Cinderella and Rogue One: A Star Wars Story, but now she is lending her voice to the project as well. Now that Angelina Jolie has been cast, the studio is searching for an actress who will play the key role of a janitor's daughter, who is instrumental in the rescue of both Stella the elephant and Ivan the silverback gorilla.

The project is based on the Newbery Medal-winning book of the same name, written by Katherine Applegate and illustrated by Patricia Castelao, which was published in 2012. The story centers on Ivan the silverback gorilla, Stella the baby elephant and a stray dog named Bob, who all live in captivity, caged up in a large shopping mall. While Ivan has no memory of life outside the mall, when the baby elephant Stella is brought in, he begins taking care of her, as memories of his former life in the wild start coming back to him. Ivan hatches a plan to escape from this place, and the clutches of their cruel and abusive owner.

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The original book is a work of fiction, but it is inspired by a bizarre true story of a real silverback gorilla named Ivan. The gorilla was born in the Democratic Republic of Congo, but he was captured as a baby and brought to live with humans. He lived with his human owners for a few years, before he began to outgrow their home, so he was placed in a 40-foot-by-40-foot glass enclosure in view of the public at the B&I shopping center in Tacoma, Washington. He lived there for the next 27 years of his life, before the animal rights group Progressive Animal Welfare Society (PAWS) lobbied for the community to boycott the shopping center after seeing the conditions he lived in, and in 1991, there was a National Geographic documentary about Ivan entitled The Urban Gorilla. In 1994, the B&I mall ultimately relinquished the rights to Ivan.

There were rumors that Michael Jackson offered to buy Ivan and let him live in his private zoo, but that was never confirmed. Ivan was ultimately placed on a permanent loan to Zoo Atlanta in 1994, although there was a large period of adjustment, where Ivan wouldn't interact with any of the other gorillas, but he was ultimately able to adjust with time and training. Ivan died at the age of 50 in 2012, as one of the oldest gorillas in captivity. It remains to be seen if any of the true story of the real Ivan will be implemented into this movie adaptation or not.

The project has been in the works for quite some time, with Mike White (School of Rock) once attached to write and direct the movie back in 2014, although now Thea Sharrock (Me Before You) is directing from Mike White's script. The project is said to be a live-action/CGI hybrid, although no further details were given from this report by The Hollywood Reporter. While Angelina Jolie is best know for her live-action movies and her work as a director, she has provided her voice for other animated movies in the past. Angelina Jolie has previously voiced Lola in Shark Tale and Tigress in all three of the Kung Fu Panda movies.