Born in Spring Valley (near New York City) as youngest of three daughters of a former dancer in American Ballet and an advertising writer. Until beginning high school in New Hampshire at 14, she lived several years with her family in Paris and in England. Obtained a B.A. degree in liberal arts from Sarah Lawrence College, where she appeared in several plays on campus. Until her first role in Out for Justice she jobbed as waitress. It took more than a year to find another role; during that time she managed to support herself from several regional theater productions and national TV ads. Until she became regular in ER, she guest starred in several TV shows and a pilot.
Majored in art history at Sarah Lawrence College; spent junior year abroad in Florence, Italy. Offered a role in Face/Off but turned it down. Dated Ron Eldard. [1991-2003] Attended grade School at Green Meadow School in Spring Valley. One of People Magazine's "50 Most Beautiful People." [1998] Is left handed. Was offered one million dollars be in Anaconda. Met her former boyfriend, Ron Eldard, in an acting class in 1991. They broke up in 2003. Was offered $27 million to renew her contract with ER but turned it down so she could move back to NYC and work in the theater. Julianna's sister, Alexandra Margulies, appeared as a stewardess in her final episode of ER. Julianna is the only cast member of ER to have ever received an Emmy award, plus she has been awarded the Screen Actors Guild Award for Outstanding Performance by a Female Actor in a Drama Series two years in a row (1998 and 1999). Has 2 Abyssinian cats. Wears a size 5 dress. Measurements: 35-23-34 (Source: Celebrity Sleuth magazine) Pregnant with her first child. Father is her fiancé, Keith Lieberthal [August 1, 2007]. Has a B.A. degree in liberal arts from Sarah Lawrence College.