Julianne was born December 3, 1960, at Fort Brag in Fayetteville, North Carolina. She is the daughter of a military judge, her father, and psychiatric social worker mother. Julianne recalls, "In grade school, I was a complete geek. You know, there's always the kid who's too short, the kid who wears glasses, the kid who's not athletic. Well, I was all three." As an Army brat, Julianne moved constantly as a child, with twenty three homes before she settled in Boston. Julianne graduated from Boston University where she earned a Bachelor of Fine Arts degree.
After graduation, Julianne headed off to New York, where she appeared in a number of late-'80's off Broadway plays. She then branched out into television with a short term part on the soap opera "The Edge of Night" which lead to a 3 year stint on "As The World Turns", for which she earned a daytime Emmy. Julianne made her first leap to the big screen with 1990's "Tales from the Darkside: The Movie".
Julianne achieved better and more powerful roles as time went on, including a small but memorable role as Harrison Ford's colleague in "The Fugitive". This small role made such an impression on Steven Spielberg that he cast her in the "Jurassic Park" sequel "The Lost World" without an audition. Director Paul Thomas Anderson, had Julianne in mind when he wrote the role of drug addicted porn star Amber Waves in "Boogie Nights". Julianne took the news saying, "It really scared me", and despite her apprehensions and misgivings about the role, she read the script and was won over. Her decision proved a wise one and she received an Oscar nomination for her astounding performance.
In 1998, Julianne played a sinister seductress in the Coen Brothers' mistaken identity farce, "The Big Lebowski". She ended the year with a subtle performance in Gus Van Sant's remake of "Psycho". Julianne was as busy as an actress can be in 1999, when she began the year with stellar performances in "Cookies Fortune", and "An Ideal Husband". She continued the year with an outstanding performance in "The End of the Affair", for which she garnered an Oscar nomination.