Marnie is a 1961 English novel written by Winston Graham, about a young woman who makes a living by embezzling from her employers, moving on, and changing her identity. She is finally caught in the act by one of her employers, a young widower named Mark Rutland, who blackmails her into marriage. Her compulsive stealing and sexual frigidity sends the troubled woman to the brink of suicide and she eventually must face the trauma from her past which is the root cause of her behavior.

It was the basis for Alfred Hitchcocks suspense film Marnie (Marnie (film)) in 1964, where the setting was changed from England to the United States of America, details of the story were changed and the ending was changed to a more optimistic one. It was also adapted into a play by Sean OConnor in 2001, and the setting was reverted back to England.

In Tony Lee Morals book Hitchcock and the Making of Marnie, Winston Graham revealed that the inspiration for "Marnie" came from three real-life incidents:

*His younger childs babysitter was a good looking girl who was constantly taking showers and getting letters from her mother about dangers of getting involved with men, and she had a strong interest in riding horses;

*A newspaper article about a woman who changed her appearance as she moved from job to job stealing money from her employers;

*A wife with three children whose husband was away at sea, slept with many sailors, became pregnant, killed the baby soon after it was born, went to trial and was acquitted by reason of temporary insanity. Soon after that, her young son started stealing things.