Tracy Kristine Nelson (born October 25, 1963 in Santa Monica, California), is an American actress.

From a prominent acting family, she is the granddaughter of Ozzie and Harriet Nelson and daughter of the late teen pop idol, Ricky Nelson. She is the sister to the Nelson twins, Matthew and Gunnar Nelson of the rock duo, Nelson.

A cancer survivor, a month after her 1987 marriage to actor William R. Moses , she was diagnosed with Hodgkin's disease.

As an actress, Tracy Nelson is best known for playing the part of 'Sister Stevie' (the sidekick of Father Dowling in the tv show of Father Dowling Mysteries ) that starred Tom Bosley of Happy Days fame and the late Mary Wickes. She started her career early playing one of Henry Fonda's daughters in Yours, Mine and Ours (1968) when she was five years old. In 1982 she gained some popularity by playing Jennifer DeNuccio on the critically acclaimed TV series Square Pegs. Through the 1980's and 1990's she made guest appearances on a string of popular television series including Family Ties, The Love Boat, St. Elsewhere, Murphy Brown, Seinfeld and Matlock. She's also appeared in several popular movies including the Nick Nolte movie Down and Out in Beverly Hills