Cynthia Ellen Nixon (born April 9, 1966) is an American actress, known for her portrayal of Miranda Hobbes in the HBO series Sex and the City (1998-2010). She is an Emmy, Tony and Grammy award winning actress.

Nixon was born in New York City, New York, the daughter of Anne Knoll, an actress, and Walter Nixon, a radio journalist. Her first onscreen appearance was as an imposter on To Tell the Truth, where her mother worked. She began acting at age 12 as the object of a wealthy schoolmate's crush in The Seven Wishes of a Rich Kid, a 1979 ABC Afterschool Special. She made her feature debut co-starring with Kristy McNichol and Tatum O'Neal in Little Darlings (1980). She made her Broadway debut as Dinah Lord in a 1980 revival of The Philadelphia Story. Alternating between film, TV and stage she did projects like the 1982 ABC-movie My Body, My Child, the features Prince of the City (1981) and I Am the Cheese (1983) and the 1982 off-Broadway productions of John Guare's Lydie Breeze. In 1985 she appeared alongside Jeff Daniels in Lanford Wilson's Lemon Sky at Second Stage Theatre.

Nixon graduated from Hunter College High School, and made theatrical history while a freshman at Barnard College in 1984, simultaneously appearing in two hit Broadway plays directed by Mike Nichols. These were The Real Thing, where Nixon played the daughter of Jeremy Irons and Christine Baranski; and Hurlyburly, where she played a young woman who encounters sleazy Hollywood executives. The two theaters were just two blocks apart and Nixon's roles were both short, so she could run from one to the other.