Julianna Luisa Margulies (; born June 8, 1966) is an American actress and producer. After several small television roles, Margulies achieved wide recognition for her role as Carol Hathaway on NBC's long-running medical drama ER, for which she won an Emmy Award. She also voiced Neera in Dinosaur (2000) and appeared in the miniseries The Mists of Avalon (2001). In 2009, she took on the lead role of Alicia Florrick in the American legal drama The Good Wife on CBS. Her performance on that show has garnered acclaim: she won the Primetime Emmy Award for Outstanding Lead Actress in a Drama Series twice, a Golden Globe, and a Television Critics Association Award. As of summer 2018, she is co-starring in the AMC dark comedy Dietland.

Margulies has won eight Screen Actor Guild Awards, making her the second most awarded woman ever within SAG after Julia Louis-Dreyfus. In 2015, TIME featured her as one of the "100 Most Influential People in the World". She was also awarded a star on the Hollywood Walk of Fame.