Julianna Margulies was born on June 8, 1966, in Spring Valley, New York, to Francesca Gardner, a ballet dancer and eurythmy teacher, and Paul Margulies, an advertising executive and writer. She is the youngest of three daughters and spent her early years in Paris and England due to her parents' careers.

She returned to the United States for high school and later attended Sarah Lawrence College, where she studied art history and participated in theatrical productions.

Julianna Margulies began her acting career with small television roles before landing a significant part as Carol Hathaway in the NBC medical drama series ER in 1994. Her performance earned her a Primetime Emmy Award and six Screen Actors Guild Awards.

She continued to work in television, appearing in shows like The Sopranos and The Mists of Avalon. In 2009, she took on the lead role of Alicia Florrick in the CBS legal drama series The Good Wife, which won her additional Emmy Awards, a Golden Globe, and more Screen Actors Guild Awards.

She has appeared in several films, including Ghost Ship, Evelyn, and Snakes on a Plane. She also starred in the National Geographic miniseries The Hot Zone and the Apple TV+ drama series The Morning Show.

Her versatility as an actress has earned her numerous accolades, including a star on the Hollywood Walk of Fame and recognition as one of Time magazine's 100 most influential people in the world in 2015.

Julianna Margulies is married to Keith Lieberthal, and they have one son together.