Jodi Lyn O'Keefe (born October 10, 1978) is an American actress and model, who at age 17 portrayed Cassidy Bridges on Nash Bridges. She is also known for her role on Prison Break as Gretchen Morgan, a.k.a. "Susan B. Anthony", and as Josette "Jo" Laughlin in The Vampire Diaries.
O'Keefe started her career as a model at the age of 8 years old, and she did some modeling work for a Jeans company. Midway through her junior year of high school, O'Keefe left school to star on the soap opera Another World, playing Marguerite "Maggie" Cory. She then got a role on Nash Bridges playing Cassidy, the daughter ofDon Johnson's title character. She and her mother moved to Hollywood so O'Keefe completed her schooling by mail. When she was 17 she had an affair with Don Johnson.
O'Keefe made her big screen debut in 1998 in Halloween H20: 20 Years Later and later starred in such films as The Crow: Salvation,Whatever It Takes and Devil In The Flesh 2. In 1999, she co-starred in the teen film She's All That (1999) as Taylor Vaughan alongside Freddie Prinze Jr. and Rachael Leigh Cook. When asked if it was hard to play her character, a high school prima donna, she replied, "Everybody knew a Taylor Vaughan in high school. Working in show business, you meet girls like that every day."
O'Keefe kept on filming both movies and Nash Bridges until the series ended in 2001. Later films have included Out for Blood, in which she played a vampire named Layla Simmons and Venice Underground. On the small screen, she has appeared in various shows including Dharma & Greg, Boston Legal, Two and a Half Men, Charmed, The Evidence,The Big Bang Theory, and Tru Calling.
In 2007, O'Keefe was cast in a starring role on the series Prison Break; she was a part of the show's cast through its third and fourth seasons. O'Keefe has said that she "truly loved" playing the part of her Prison Break character Gretchen Morgan, because it "challenged" her, and because Gretchen was the "polar opposite of her" and "was badass".
In 2014 O'Keefe was cast in a recurring role in VH1's TV series Hit the Floor, and appeared in the film Merry ExMas. The same year, she was also cast in the recurring role of Jo in the sixth season of The CWseries The Vampire Diaries.