Lisa Olivia Munn was born in Oklahoma. She is of Chinese descent on her mother's side (though her mother was raised in Vietnam) and of German-Irish descent on her father's. When Munn was two, her mother re-married, this time to a man in the United States Air Force. Although the family relocated many times, Munn was predominantly raised in Tokyo, Japan, where the military assigned her stepfather. During this time, she had appeared in a number of local theater productions, and later became a model within the Japanese fashion industry. She also attended the University of Oklahoma, majoring in journalism and minoring in Japanese and dramatic arts.
Munn moved back to the United States, settling in Los Angeles, California to pursue an acting career. In 2004, she interned at Fox Sports Net and worked as a sideline reporter for college football and women's basketball. She has gone on to say that she disliked the experience, explaining "I was trying to be something I wasn't, and that made me really uncomfortable on live TV."