Gwen Stefani auditioned for Angelina Jolie's role in the 2005 film Mr. & Mrs. Smith.
During an appearance on The Ellen DeGeneres Show on Wednesday, the singer participated in a round of Burning Questions.
As part of the round, host Ellen asked Gwen whether there was a movie role people would be surprised to learn she auditioned for.
"Mr. & Mrs. Smith - Angelina beat me," she answered, to which Ellen replied: "Wow, that could have gone a whole different way. Talk about Sliding Doors."
Directed by Doug Liman, Mr. & Mrs. Smith starred Angelina and Brad Pitt as a bored married couple who find out that they're assassins working for competing agencies and have been assigned to kill each other.
But while the film was a hit at the box office, it is perhaps better known for establishing one of Hollywood's most publicised scandals as Angelina was accused of causing the divorce of Brad and Jennifer Aniston, an allegation she denied.
In addition to her music career, Gwen played Jean Harlow in 2004's The Aviator and voiced DJ Suki in the animated movie Trolls.