[1] In the original timeline, Jean is visited by Charles Xavier (Patrick Stewart) and Erik Lehnsherr (Ian McKellen) after her parents had been concerned about what they believed to be a type of "illness" in their daughter.

The girl is shown levitating multiple cars and other objects with her telekinetic powers and the two elder mutants, still friends at the time, invite Jean to the Xavier School for Gifted Youngsters.

[3] Since director Bryan Singer had gone with a younger, teenage portrayal of Rogue (Anna Paquin), he felt that he wanted a more mature Jean in contrast.

Simon Kinberg was disappointed by this outcome, calling the Dark Phoenix Saga "the ultimate X-Men story" and compared reducing it to a secondary subplot to sidelining the Book of Genesis chapter from The Bible.

However, the producers were unhappy with the outcome of X-Men: Apocalypse and cancelled the second sequel, forcing Simon Kinberg to compress his storyline into one film.

[12] Ashley Judd, Alicia Witt, Selma Blair, Robin Wright-Penn, Minnie Driver and Maria Bello were also all rumoured to have been auditioning for the role at the time.

[13][14] Lucy Lawless was invited to audition, possibly for the role of Jean, but choose to abstain due to her real life pregnancy and her otherwise busy schedule with Xena: Warrior Princess.

[15] In early August 1999, it was reported by Daily Variety that Dutch model turned actress Famke Janssen had been cast as Jean Grey.

[14] For X-Men: Apocalypse (2016), Hailee Steinfeld, Elle Fanning, Chloë Grace Moretz[16] and Saoirse Ronan[17] had been among those who auditioned for the role of the younger Jean.

[20] In X-Men: The Last Stand, Jean's appearance when the Phoenix takes control was created by John Bruno working with Moving Picture Company.

MPC made hundreds of skin and eye treatments and used a 3D model of Famke Janssen's face when compositing them into Jean's digital makeup.

"[24] Hugh Armitage and Simon Reynolds of Digital Spy called Sophie Turner's portrayal of Jean Grey "hugely likable" across X-Men: Apocalypse.