Mark Millar MBE is a Scottish comic book writer born on 24 December 1969. He gained prominence with his work on the superhero series The Authority, published by DC Comics' Wildstorm imprint. Millar has a significant body of work with Marvel Comics, including notable runs on The Ultimates, X-Men, Fantastic Four, and Avengers. His series The Ultimates was named "the comic book of the decade" by Time magazine and served as a major inspiration for the 2012 film The Avengers. Millar also wrote the Civil War miniseries, which was the backbone for the Marvel Cinematic Universe film Captain America: Civil War. Another one of his storylines, Old Man Logan, inspired the film Logan.

Millar is also known for his creator-owned series published under the Millarworld label, such as Wanted, Kick-Ass, Nemesis, Superior, Supercrooks, and The Secret Service. Many of these series have been adapted into films and series, such as Wanted, Kick-Ass, and Kingsman: The Secret Service. In 2017, Netflix acquired Millarworld, with plans to adapt Millar's creations.

In addition to his writing, Millar acts as an executive producer on film and television adaptations of his work. From 2012 to 2016, he was a creative consultant for 20th Century Fox for Marvel property adaptations. In 2013, Millar was appointed a Member of the Most Excellent Order of the British Empire (MBE) for his contributions to film and literature.