Jim Carrey - Truman Burbank
Jim Carrey initially shot to fame when he went from the television show In Living Color to star in Ace Ventura: Pet Detective. However, before then he had appeared in such movies as the vampire film Once Bitten and Francis Coppola's Peggy Sue Got Married. He was with Clint Eastwood's Dirty Harry as one of the victims of a serial killer in The Dead Pool. He also had a serious role in the television drama Doing Time on Maple Drive. Since Ventura, notable films include The Mask, Liar, Liar, and Man on the Moon.
Ed Harris - Christof
Ed Harris was called in at the last moment to replace Dennis Hopper in the role of Christof, the creator of The Truman Show. Harris was first noticed by many when he played astronaut John Glenn in The Right Stuff. Some of his better roles since then have been in The Abyss, Jacknife, State of Grace, and Apollo 13. In 2000, he produced, directed, and starred in Pollock. He has been nominated for three Academy Awards, twice for his supporting roles in Apollo 13 and The Truman Show, and once for the lead role in Pollock.

Laura Linney - Meryl Burbank
Laura Linney's first feature films included tiny roles in the wonderful movies Lorenzo's Oil and Searching for Bobby Fischer. She received more attention when she played one of the leads in the rather wretched Congo. Since then she has appeared with Richard Gere in Primal Fear and with Clint Eastwood and Ed Harris in Absolute Power. She received her first Academy Award nomination for her role in You Can Count on Me.

Natasha McElhone - Sylvia
Natasha can be seen with Anthony Hopkins in Surviving Picasso as well as the Harrison Ford / Brad Pitt drama The Devil's Own. After Truman Show she could be seen in the Robert De Niro film Ronin as well as Kenneth Branagh's Love's Labour's Lost.

Noah Emmerich - Marlon
Before The Truman Show, Noah could be seen in Beautiful Girls and CopLand. Since then, he has had roles in Crazy in Alabama, Life, Frequency, and John Woo's Windtalkers.