Louise Fletcher was born as the daughter of deaf parents, Robert and Estelle Fletcher, so to speak, she was taught by a hearing aunt who brought them into contact with acting. After graduating from the University of North Carolina, she was drawn to Los Angeles in California, where she worked as a secretary by day and took acting classes at night. This was followed by appearances in several television productions, until she married in 1960 and needed time for her family.

1974 Louise Fletcher turned in Robert Altman's Thieves Like Us Back to the film. Milos Forman saw her and casted her for the role of the tyrannical head nurse Ratched in One Flew Over the Cuckoo's Nest, for which they have a Oscar for Best Actress and a Golden Globe as best actress received in a drama. The American Film Institute conducts its figure of the nurse Ratched as number five on the list of 100 best movie villains of all time. Fletcher also went on in movies such as The Vineyard snoopers, Exorcist II - The Heretic (1977), The Devil's Fire, Brainstorm (1983), Invaders from Mars, flowers of the night and Natural Enemies (with Peter Armstrong and Hal Holbrook).

For her recurring role in the television series Picket Fences, she was nominated for an Emmy. She also had a recurring role in the science fiction series Star Trek: Deep Space Nine, as Kai Winn, the religious leader of the Bajoran.

Louise Fletcher was married from 1960 until the divorce in 1978 with producer Jerry Bick, and has made this marriage two sons. She caused a stir when she received after her divorce, an affair with the more than 25 years younger, and then 21 years old Morgan Mason, son of actor James Mason.