Julie Anne Smith (born December 3, 1960), known professionally as Julianne Moore, is an American actress. She is particularly known for her portrayals of emotionally troubled and vulnerable women. Prolific in independent films and blockbusters since the early 1990s, she is the recipient of numerous accolades, including an Academy Award, a BAFTA Award, two Emmy Awards, and two Golden Globe Awards. She is one of only two actresses to win the Best Actress award at all three major European film festivals—Cannes Film Festival, Berlin Film Festival, and the Venice Film Festival.

After studying theater at Boston University, she played a regular in the soap opera As the World Turns from 1985 to 1988, earning a Daytime Emmy. Moore made her breakthrough with Robert Altman's ensemble film Short Cuts (1993), followed by a critically acclaimed performance in Todd Haynes' Safe (1995). Starring roles in the blockbusters Nine Months (1995) and The Lost World: Jurassic Park (1997) established her as a Hollywood leading lady. She received Oscar nominations for her roles as a 1970s pornographic actress in the drama film Boogie Nights (1997) and emotionally unsatisfied housewives in the period dramas The End of the Affair (1999), Far from Heaven (2002), and The Hours (2002).

Moore's career progressed with roles in The Big Lebowski (1998), Magnolia (1999), Hannibal (2001), Children of Men (2006), A Single Man (2009), The Kids Are All Right (2010), Crazy, Stupid, Love (2011), and Maps to the Stars (2014). She won a Primetime Emmy for playing Sarah Palin in the HBO film Game Change (2012), and the Academy Award for Best Actress for her portrayal of an Alzheimer's patient in Still Alice (2014). Her highest-grossing releases came with the final two films in The Hunger Games film series (2014–2015) and the spy film Kingsman: The Golden Circle (2017). Since then she starred in independent films and streaming projects including Haynes' drama May December (2023), the historical drama miniseries Mary & George (2024), and the black comedy limited series Sirens (2025).

In addition to acting, Moore has written a series of children's books about a character named Freckleface Strawberry. She is married to director Bart Freundlich and they have two children. In 2015, Time named her to its 100 most influential people in the world list and in 2020, The New York Times named her one of the greatest actors of the 21st century.

Julie Anne Smith was born on December 3, 1960, at Fort Bragg, North Carolina. Her father, Peter Moore Smith, a paratrooper in the U.S. Army during the Vietnam War, attained the rank of colonel and became a military judge. Her mother, Anne (née Love 1940–2009), was a psychologist and social worker from Greenock, Scotland, who had migrated with her family to the United States in 1951. Moore has a younger sister and a younger brother, the novelist Peter Moore Smith. Having a Scottish mother, Moore claimed British citizenship in 2011 in her honor.

Due to her father's occupation, Moore frequently moved around the United States as a child. She was close with her family as a result, but says that she never had the feeling of coming from one particular place. The family lived in multiple locations including Alabama, Georgia, Texas, Panama, Nebraska, Alaska, New York, and Virginia, and Moore attended nine different schools. The constant moving around made her an insecure child, and she struggled to establish friendships. In spite of the difficulties, Moore has remarked that an itinerant lifestyle was beneficial to her future career: "When you move around a lot, you learn that behavior is mutable. I would change, depending on where I was... It teaches you to watch, to reinvent, that character can change."

When Moore was 16, the family moved from Falls Church, Virginia, where Moore was attending J.E.B. Stuart High School, to Frankfurt, West Germany where she went to Frankfurt American High School. She was clever and studious, a self-proclaimed "good girl", and she planned to become a doctor. She had never considered performing or even attending the theater, but she was an avid reader which led her to begin acting in school productions. Moore appeared in several plays including Tartuffe and Medea, and with the encouragement of her English teacher, she chose to pursue a theatrical career. Her parents supported her decision, but asked that she train at a university to provide the added security of a college degree. She was accepted into the Boston University College of Fine Arts in Boston and graduated in 1983 with a Bachelor of Fine Arts in theater.

"There was already a Julie Smith, a Julie Anne Smith, there was everything. My father's middle name is Moore; my mother's name is Anne. So I just slammed the Anne onto the Julie. That way, I could use both of their names and not hurt anyone's feelings. But it's horrible to change your name. I'd been Julie Smith my whole life, and I didn't want to change it."