And now an incredible set of 11 never-before-seen photographs of the iconic actress have come to light, showing her in full colour on the set of Some Like It Hot, the hit movie originally shot in monochrome.
In the pictures, taken in 1959, Marilyn is seen relaxing between shoots under a parasol, oozing glamour in white fur and diamonds. Another snap sees her chatting to her handsome co-star Tony Curtis.
The series of photos are hitting the headlines thanks to a 'Hollywood Legends' auction taking place in Las Vegas in June.
Held by Julien's Auctions, the two-day sale also features other high-profile lots; from Christopher Reeves' full Superman costume, to Mel Gibson's Braveheart outfit, sword and shield, and the earrings worn by Kate Winslet in Titanic.
Alongside the unique images of Marilyn, fans will also be able to bid for personal items belonging to the blonde bombshell, including her Something's Got To Give prompt book, and a bottle of her Chanel No5 perfume.
Speaking about the one-off pictures – taken on location in Florida by a journalist – auctioneer Darren Julien said: "In the slides Marilyn appears to relax between takes on the beach."
"She is wearing the revealing dress in which her character attempts and succeeds to seduce Curtis' character."
Some Like It Hot, starring Tony - father of actress Jamie Lee Curtis with ex-wife Janet Leigh - and Jack Lemmon, tells the story of two musicians fleeing for their lives after witnessing a mob hit. The pair decide to disguise themselves as women in a female band so they don't get caught.
At the 1960 Golden Globes, Marilyn won the best actress in a musical or comedy for her turn in the film as 'Sugar' Kane Kowalczyk, while Jack was named best actor.