Most famous as a Playboy model, Witmer is also known for her appearances on the VH1 reality shows Rock of Love and I Love Money, as well as for her photo shoots for Sports Illustrated and Vanity Fair.
Early in her career, she was photographed for the covers of Glamour, FHM, and Muscle & Fitness magazines.
In 2006, she appeared in eight episodes of the game show Deal or No Deal.
Though she was born in the Los Angeles suburb of Valencia, California, she was raised primarily in Dublin, Ohio. After graduating from high school, she returned to the Los Angeles area to find modeling work.
She appeared in one of rapper Eminem's music videos.