Nixon started her career at the age of 14, acting in a movie named Little Darlings. Around that time, she also started appearing on theater plays on and off Broadway. At Broadway, she has participated in many plays, among them Hurly Burly, The Real Thing, The Heidi Chronicles, and Who's Afraid of Virginia Woolf. For her participation in the latter, she earned a Los Angeles Drama Critics Award.
Nixon has been nominated at various times for awards and critically praised for her characterization of Miranda in Sex and the City, which will soon begin its sixth season.
Her filmography/television resume goes as follows: