Isabel Gillies (born February 9, 1970, in New York City, New York) is an actress and author. She played Elliot Stabler's wife, Kathy, in Law & Order: Special Victims Unit from 1999-2011. In 2009, Scribner published Happens Every Day, her New York Times bestselling memoir.
Gillies landed her first movie role in 1990 when Whit Stillman cast her in his pioneering independent film, Metropolitan. She played the role of Cynthia McLean. Other film credits include Alison in I Shot Andy Warhol (1996), Moira Ingalls in On Line (2002), Isabel in Happy Here and Now (2002), and Kathryn in New Orleans, Mon Amour (2008).
Prior to her role on SVU, Gillies appeared in "Bad Girl," an episode of the original Law & Order series, playing a young woman who murders an undercover police officer and then undergoes a religious conversion during her trial and is born again. In 2000, she played the role of Alison in the short-lived Fox series The $treet.
Gillies's memoir, Happens Every Day, is about her leaving New York to follow her first husband to Oberlin College, only to see her marriage suddenly crumble. Happens Every Day was a New York Times bestseller and featured by Starbucks as a nationwide selection