Munn began her professional career in television journalism before becoming an actress.
In 2006, Munn starred as Mily Acuna on the series Beyond the Break. from 2006 to 2010 and was a correspondent on The Daily Show from 2010 to 2011.
The commercials show Munn experiencing acne herself.
Since January 2015, she has been the voice of the character Phoebe Callisto on the Disney Junior animated series Miles from Tomorrowland.
Munn has appeared in advertising campaigns for Nike, Pepsi and Neutrogena.In 2006, Munn moved on to the G4 network, where she began co-hosting Attack of the Show! Although she admits video games were her "weak point," she was confident in her technical knowledge.On the show, Munn was featured with journalist Anna David in a segment called "In Your Pants," which deals with sex and relationship questions from viewers. , Munn hosted Formula D, a now defunct program about American drift racing, and an online podcast called Around the Net, formerly known as The Daily Nut, for G4. in December 2010 and was replaced by Candace Bailey.Munn had a significant role in the horror film Insanitarium in which she played a nurse at an insane asylum.She had roles in the films Date Night (2010) and Iron Man 2 (2010). praised Munn for her improvisation skills and led the crew in a round of applause.