Zea was born in Harris County, Texas, attending high school in Monahans, graduating in 1993. She graduated from the American Musical and Dramatic Academy in New York City in 1995. Also in 1995, Zea co-starred as Lana Tisdel in the short film Boys Don't Cry. In the 1999 feature film version of Boys Don't Cry the role was played by Chloë Sevigny. She also appeared in many national commercials for companies such as Dove, Snickers and Hellman's Salad Dressing.
Zea began her career in an Off-Broadway theatre, appearing in productions of The Three Sisters and A Midsummer Night's Dream. She made her feature debut in the Shakespeare-themed independent drama Macbeth in Manhattan in 1999. In the following year, Zea made her television debut in an episode of short-lived The WB drama series, D.C.. Later in that year she was cast as Gwen Hotchkiss Winthrop, a businesswoman and socialite, and the member of the wealthy Hotchkiss family, in the NBC daytime soap opera Passions. She appeared in the show on a regular basis from November 15, 2000 to October 3, 2002. On her leaving, Zea said "I have decided not to renew my contract with Passions. Although I enjoyed my experience, and learned quite a bit, especially initially, I know that the best thing for my career, and my craft, is to pursue new challenges. So after some deliberation, an amicable parting of ways seemed to be the best decision". Zea is the second Actress who played the role of Gwen. Susan Lucci's daughter Liza Huber played the role from July 5, 1999 to November 8, 2000, and again, after Zea left the show.
In 2004, Zea was cast in a recurring role in the FX police drama series, The Shield. She played the role of Lauren Riley, a love interest of Michael Chiklis' character Vic Mackey. The following year, Zea won her first series regular role on primetime television, on the ABC drama series, Eyes opposite Tim Daly. The series was canceled after a single season. Her next major role was on the ABC primetime soap opera/comedy-drama Dirty Sexy Money opposite Jill Clayburgh, Donald Sutherland and Peter Krause. Zea played spoiled socialite Karen Darling. The soap aired from 2007 to 2009, and was canceled after two seasons. In 2009, she had a recurring role during the first season of the HBO comedy series Hung. She also had many guest-starring roles, on CSI: Crime Scene Investigation, Two and a Half Men, Without a Trace, Medium, Franklin & Bash, and Person of Interest.
In 2010, Zea began starring as series regular during the first three seasons of the FX drama Justified, changing to a recurring role from Season 4. She played the role of Winona Hawkins, the ex-wife of Raylan Givens. Zea originally was a guest star in the pilot for Justified, but was upped to regular right after the pilot with a two-year deal. Alongside her regular role on Justified, from 2012 to 2013, Zea had the recurring role on Showtime comedy-drama, Californication as a new love interest for David Duchovny' character. In film, Zea had supporting role in the 2010 comedy The Other Guys. As lead Actress, she co-starred alongside Sean Patrick Flanery in the 2011 independent thriller InSight, and in the Lifetime movie Burden of Evil (2012).
In 2013, Zea starred in the major role of Dr. Claire Matthews, the estranged wife of a serial killer in the Fox drama series, The Following. She returned to show in second season on a recurring basis. Also in 2013, she had a recurring role as Maxine Seagrave, a drug and gambling kingpin, on the first season of CBS summer series, Under the Dome. Later in that year, Zea was cast in her first series leading role of the Amazon comedy pilot The Rebels. The pilot premiered in February 2014, but not was picked up to series. Later in that year, Zea was cast in two independent films: Too Late in the female lead role opposite John Hawkes, and The Grey Lady as lead character.
In June 2013, Zea announced her engagement to her former co-star in Passions, Travis Schuldt, after 10 years of dating. The couple married on July 16, 2014, in Hawaii. In June 2015, they announced they were expecting their first child together. In October, 2015, Zea gave birth to a daughter named Reygan.
