Messing was born in the New York City borough of Brooklyn to Jewish American parents Brian Messing, a sales executive for a jewelry manufacturer, and Sandra, who has worked as a professional singer, banker, travel and real estate agent. When Messing was three, she moved with her parents and her older brother, Brett, to East Greenwich, a small town outside Providence, Rhode Island.

During her high school years, she acted (and sang) in a number of high school productions, including the starring role in the musical "Annie" and "Fiddler On the Roof". Messing took lessons in dance, singing, and acting. While her parents encouraged her dream of becoming an actress, they also urged her to complete a liberal arts education before deciding on acting as a career. Following their advice, she attended Brandeis University in Waltham, Massachusetts. During her junior year, she studied theater at the prestigious London-based British European Studio Group program, an experience that fueled her desire to act.

In 1990, after graduating summa cum laude from Brandeis with a bachelor's degree in theater arts, Messing gained admission to the elite Graduate Acting Program (which accepts only about 15 new students annually) at New York University, where she earned a master's degree in fine arts after three years.


In 1993, Messing won praise for her acting in the pre-Broadway workshop production of Tony Kushner's much-lauded play Angels in America: Perestroika. Consequently, she appeared in several episodes of the television series NYPD Blue during 1994 and 1995.

In 1995, Messing made her film debut with a relatively small but important role in Alfonso Arau's A Walk in the Clouds playing the unfaithful wife of Keanu Reeves. This exposure led the Fox network to make her the co-star of the television sitcom, Ned and Stacey. The series lasted for two seasons, from 1995 to 1997. Messing appeared as Jerry Seinfeld's date in two episodes of the series Seinfeld: "The Wait Out" in 1996 and "The Yada Yada" in 1997. Messing turned down a starring role in another television sitcom to appear in Donald Margulies's two-character play Collected Stories, which opened at the Off-Broadway Manhattan Theater Club in 1997.

In 1998, Messing played a lead role as the bio-anthropologist "Sloan Parker" on ABC's dramatic science fiction television series Prey. During this time her agent approached her with the pilot script for the television show Will & Grace. Messing was inclined to take some time off, but the script intrigued her, and she auditioned for the role of Grace Adler, beating out Nicollette Sheridan who later guest starred on the show as a romantic rival of Grace's. Will & Grace became a big ratings success, and Messing gained renown.

In 2002, she was named one of the "50 Most Beautiful People in the World" by People Magazine. TV Guide picked her as its "Best Dressed Woman" in 2003. Messing was cast by director Woody Allen in a small role in his 1998 film Hollywood Ending. Her film roles since include a happily married but ill-fated wife in the supernatural thriller The Mothman Prophecies (2002) and a supporting role in Along Came Polly (2004).

The Wedding Date (2005) was Messing's first leading role in a high-profile film. It received mixed reviews but performed fairly well at the box office. Messing was featured as a judge on the season finale of the second season of Bravo's reality show, Project Runway. She also starred in the television mini-series The Starter Wife which was nominated for 10 Emmy awards including one for Messing for Outstanding Lead Actress in a Miniseries or Movie.