Casting can define a film’s legacy, shaping not only how a story is told but also how it’s remembered for generations. While some performances now seem inseparable from the actors who gave them, many iconic roles were almost played by entirely different people.
The original contenders were massive stars in their own right, bringing the tantalizing question of how the tone, reception, or even success of the film might have changed.
La La Land – Miles Teller and Emma Watson as the Leads

Getty Images
Before Ryan Gosling and Emma Stone became the faces of La La Land, director Damien Chazelle had planned to cast Miles Teller and Emma Watson. Contractual issues and creative differences led to the switch. Gosling and Stone’s chemistry was undeniable, earning the film six Academy Awards and worldwide acclaim.
The Godfather – Jack Nicholson as Michael Corleone

IMDb
Jack Nicholson turned down the role of Michael Corleone, saying he believed the part should go to an Italian-American actor. That decision paved the way for Al Pacino, whose quiet intensity and cold transformation became one of cinema’s most unforgettable performances. Nicholson later expressed no regrets, acknowledging Pacino’s brilliance.
The Silence of the Lambs – Michelle Pfeiffer as Clarice Starling

IMDb
Jonathan Demme initially offered the role of Clarice Starling to Michelle Pfeiffer after working with her on Married to the Mob. Pfeiffer declined, uncomfortable with the film’s dark subject matter. Jodie Foster, eager for the role, stepped in and delivered a career-defining performance that earned her an Academy Award.
Star Wars – Al Pacino as Han Solo

Getty Images
Al Pacino was offered the role of Han Solo in Star Wars: A New Hope but turned it down because he didn’t understand the script. He later joked that he gave Harrison Ford a career. Ford’s cocky yet charming portrayal became one of the most iconic characters in sci-fi history.
The Notebook – Britney Spears as Allie

Getty Images
During early development of The Notebook, pop star Britney Spears auditioned for the role of Allie Hamilton. Casting tapes revealed Spears reading alongside Ryan Gosling, who had already been cast as Noah. Ultimately, Rachel McAdams secured the role, delivering a performance that resonated with audiences worldwide.
Forrest Gump – John Travolta as Forrest

Getty Images
Tom Hanks’ career-defining role in Forrest Gump was initially offered to John Travolta. Travolta declined, later admitting it was a mistake. Hanks brought a nuanced depth to the character that earned him an Oscar, helping cement the film’s place as a modern classic.
Black Widow – Emily Blunt as Natasha Romanoff

Getty Images
Emily Blunt was the original choice for Natasha Romanoff, aka Black Widow, in the Marvel Cinematic Universe. However, scheduling conflicts with Gulliver’s Travels forced her to drop out. Scarlett Johansson then stepped in and made the role her own across more than a decade of MCU films.
Pretty Woman – Molly Ringwald as Vivian

Getty Images
Before Julia Roberts became synonymous with Pretty Woman, Molly Ringwald was offered the role of Vivian. She turned it down, reportedly uncomfortable with the original darker tone of the script. The film was later reworked into a romantic comedy, and Roberts’ performance propelled her to A-list status.
The Devil Wears Prada – Rachel McAdams as Andy Sachs

Getty Images
Rachel McAdams was the top choice for Andy Sachs in The Devil Wears Prada, but she declined multiple offers, wanting to avoid mainstream commercial roles at the time. Anne Hathaway, who campaigned heavily for the role, eventually landed it and brought warmth and relatability to the ambitious assistant opposite Meryl Streep’s icy Miranda Priestly.
Iron Man – Tom Cruise as Tony Stark

Getty Images
Long before Robert Downey Jr. suited up, Marvel had eyed Tom Cruise for Tony Stark. Cruise was interested but ultimately declined due to script concerns and a lack of creative control. Downey’s casting was initially met with skepticism but ended up launching the Marvel Cinematic Universe into a global juggernaut.