A cast list on a poster looks settled. Behind the scenes, it often isn’t, and sometimes the person you see on screen wasn’t the first choice, or even the second.
The recasts below happened after cameras were already rolling, or in some cases after much of the footage existed. The reasons range from illness and injury to creative differences and tragedy.
1. The Tin Man in The Wizard of Oz (1939)

Buddy Ebsen was originally cast as the Tin Man, after trading places with Ray Bolger, who had first been set to play the Tin Man and ended up as the Scarecrow. The silver makeup at the time used aluminum powder. Ebsen reacted badly to it and ended up in hospital with breathing trouble.
Jack Haley took over the part. The makeup was changed to an aluminum paste, which was safer to wear. Haley’s performance is the one audiences have known ever since.
2. Annie Oakley in Annie Get Your Gun (1950)

Judy Garland was cast as the sharpshooting lead at MGM. Production started in 1949, but her work on the film was troubled, and the studio removed her from the project.
Betty Hutton stepped in and played Annie Oakley. The film was released in 1950 and became a commercial success for the studio. Garland’s brief time on it remains a well known footnote in her career.
3. Major Kong in Dr. Strangelove (1964)

Peter Sellers was already playing several parts in Stanley Kubrick’s Cold War satire, and the plan included him as the bomber pilot Major Kong too. Then he injured his ankle, which made it hard to work inside the cramped bomber set.
Slim Pickens, a veteran of Westerns, replaced him. His cowboy hat and wild ride on the bomb became one of the film’s most famous images. Sellers still played Mandrake, President Muffley and Dr. Strangelove himself.
4. Captain Willard in Apocalypse Now (1979)

Harvey Keitel was first hired to play Captain Willard, the soldier sent up the river to find Colonel Kurtz. Francis Ford Coppola was unhappy with how the performance was shaping up early in the shoot, and Keitel left.
Martin Sheen replaced him. The production that followed in the Philippines was famously difficult, and Sheen suffered a serious heart attack during it. The film was eventually completed and released in 1979.
5. Marty McFly in Back to the Future (1985)

Eric Stoltz was cast as Marty McFly and shot for roughly five weeks. Director Robert Zemeckis and the producers decided his more intense approach didn’t fit the comedy they wanted.
Michael J. Fox had been the original choice, but his television commitments on Family Ties got in the way at first. A schedule was worked out so that he could film the movie in the evenings and at night. Scenes with Stoltz were reshot.
6. Vicki Vale in Batman (1989)

Sean Young was initially cast as the photojournalist Vicki Vale in Tim Burton’s Batman. She was injured in a riding accident and couldn’t continue with the role.
Kim Basinger took over the part. Her casting came at a time when the production was already underway, and she appeared opposite Michael Keaton and Jack Nicholson. The film was a major hit in 1989.
7. Donkey and Shrek in Shrek (2001)

Chris Farley was voicing the title ogre and had recorded a substantial amount of dialogue when he died in December 1997. The animation team had also started work using his performance.
Mike Myers was brought in as the replacement and gave Shrek a Scottish accent. The film was reworked substantially from there. It opened in 2001 and won the first Academy Award for Best Animated Feature.
8. Aragorn in The Lord of the Rings: The Fellowship of the Ring (2001)

Stuart Townsend was cast as Aragorn and began work in New Zealand. Only a few days into filming, the filmmakers decided he was too young for the part, and he left.
Viggo Mortensen was asked to step in at very short notice. He joined the production quickly and played the role across all three films. Peter Jackson’s trilogy was filmed together over a long single shoot.
9. Tony in The Imaginarium of Doctor Parnassus (2009)

Heath Ledger died in January 2008 while Terry Gilliam’s film was only partway through production. The role of Tony moves through a magical mirror in the story, which gave the director a way to continue.
Johnny Depp, Jude Law and Colin Farrell each played versions of the character in the mirror world. The three actors reportedly gave their pay to Ledger’s daughter. The film was released in 2009.
10. J. Paul Getty in All the Money in the World (2017)

Kevin Spacey had played the oil tycoon J. Paul Getty, and Ridley Scott’s film was finished and nearly ready for release. After allegations against Spacey surfaced in late 2017, Scott chose to recast the part rather than shelve the movie.
Christopher Plummer replaced him, and the scenes were reshot in a matter of days. The film still came out in December 2017. Plummer received an Academy Award nomination for the performance.