Moran's first acting role was at the age of five, in a television commercial for First Federal Bank. At the age of six, she was cast as Jenny Jones in the television series Daktari, which ran from 1966 to 1969. She made her feature-film debut in How Sweet It Is! (1968) with Debbie Reynolds, and made regular appearances on The Don Rickles Show in 1972, and guest appearances in The Courtship of Eddie's Father, My Three Sons, Bearcats!, and Family Affair. As a young child, she also appeared in the television series Gunsmoke.
In 1974, at the age of 13, Moran was cast to play her best known role, Joanie Cunningham on the sitcom Happy Days, the feisty younger sister of Richie Cunningham (Ron Howard). Moran continued the role in 1982, in the short-lived spin-off series Joanie Loves Chachi, alongside Scott Baio, although she later stated that she had only reluctantly agreed to star in the series; she would have preferred to remain with Happy Days. She won the Young Artist Award for Best Young Actress in a New Television Series for her role. After Joanie Loves Chachi's cancellation in 1983, she returned to Happy Days for its final season.
In 1983, Moran said in an interview that the Happy Days producers had pressured her to change from about the age of 15: they had "suddenly wanted me to lose weight and become this sexy thing."
2019
as Yolanda
2011
as Mrs. Klien
2011
as Herself
2005
as Self - Contestant
2003
as Self
1998
as Self
1996
as Erin Moran
1993
as Cynthia Bennett
1984
as Maggie Roberts
1982
as Joanie Cunningham
1981
as Bonnie Lee Jordan
1981
as Alumna
1979
as Herself
1977
as Joanne Morgan
1977
as Carrie Walker
1977
as Barbara Blatnick
1974
as Self
1974
as Joanie Cunningham
1973
as Tracy Schilling
1970
as Janice Gerber
1969
as Marge as a Child (uncredited)
1969
as Kim
1969
as Emily Ruth Gustafson
1968
as Laurie
1967
as Little Girl on Tricycle
1966
as Jenny Jones
1960
1955
as Rachel Parker
1955
as Jenny