Marnie was born and raised in Minneapolis, Minnesota and went to a public school and the Children's Theatre School. On leaving school, she attended the Principia Arts College.
Marnie's parents were not involved in acting, but they were both musical. Marnie has a great singing voice and it was because singing came so naturally to her that she found it was not satisfying enough on its own. This led her to acting and she has worked extensively in all mediums.
While working with the Seattle Repertory Company in 1979 Marnie met her future husband, John de Lancie. She was appearing in a production of Heartbreak House which John went to see. As he tells it, he thought Marnie spoke very well, her acting was 'not bad' and he finally noticed she was also pretty! Marnie started to receive flowers from her then anonymous admirer. A week later there was an invitation to join him for dinner which she accepted. They have since worked together in a number of productions, including 2 very special ones - their sons Keegan and Owen.
Marnie has made many stage appearances, including Cloud 9 for the LA Stage Company in 1983. She won the LA Drama Critics Award (the Los Angeles equivalent to New York's Tony Award) for this and in 1985 was a finalist in the Metropolitan Opera Competition. Marnie has also appeared in a New York stage production of A Little Night Music.
Her TV appearances include "Remington Steele," "Dallas," "Knotts Landing," "Hunter" and the Star Trek: The Next Generation episode, "Loud As A Whisper." She currently provides several voices for TV animation productions.
Marnie's film work has included movies like "Hero," where she appeared with Geena Davis and Andy Garcia and also provided the singing voice for Jessica Rabbit for Walt Disney Pictures.
Marnie has been working with her husband,
John de Lancie, on their Alien Voices Presents project. Alien Voices
presents a dramatic reading of
Sir Arthur Conan Doyle's The Lost World
Marnie Mosiman as Gladys Hungerton, in Alien Voices: The Time
Machine, The Invisible Man, and The First Men in the Moon.