She is best known for her television roles as Brenda Barrett on General Hospital, Gina Kincaid on Beverly Hills, 90210, and Sam Marquez on Las Vegas.
[4] Marcil acted in a number of theatre productions before landing the role of Brenda Barrett on the soap opera, General Hospital, in 1992.
In 1998, after six years on General Hospital, she left the show to star in the made-for-television movie, To Love, Honor and Deceive and had a recurring guest role on the police drama High Incident, which was produced by Steven Spielberg.
However, after her first appearance in "Johnny Got His Gold,” the show decided to redo the role and replaced Marcil with Jacqueline Obradors, as Detective Rita Ortiz.
Marcil made one more cameo appearance, as Detective Olivera, in the 11th-season episode, "Shear Stupidity.” From 2002 to 2003, she returned to General Hospital, as Brenda Barrett, garnering her a Daytime Emmy Award for Outstanding Supporting Actress in 2003.
Vanessa later joined the cast of the NBC drama Las Vegas as Sam Marquez, a casino host, where she remained on the show for five seasons until 2008.
In 2014, she starred in the Hallmark channel movie, Stranded in Paradise, and in 2015, she joined the cast of the Pop reality series, Queens of Drama, about the lives of former soap-opera actresses attempting to pitch a pilot for a television network.