Daughter of 'Steven Tyler' of the band Aerosmith and Bebe Buell, former model (and Playboy Playmate of the Month) and stalwart of the backstage rock scene of the 1970's, Liv grew up thinking that rock star Todd Rundgren was her father. But as she was growing up Tyler began dropping by to visit, and Liv noticed that his daughter Mia looked enough like her to be her twin. She confronted her mother, and was told the truth; by the time she was 12 she had taken her father's name.

At 14 she and her mother left Portland, Maine for New York, where she got her start as a model. After only on year in the business she was offered the part of Callie in Heavy after a single reading, and only three weeks later was cast in Silent Fall James Mangold, director of Heavy, delayed shooting until Liv became available.

Appearing in Empire Records with Renee Zellweger, the 90's saw her career come alive. She followed Empire Records with the highly acclaimedStealing Beauty, One Night at McCool's and Armageddon, which propelled her into stardom. With her most recent role in Lord of the Rings, Liv has guaranteed herself a place in the minds of Americans.