Olive Thomas was an American silent-film actress, art model, and photo model. Once she was the world's biggest sex symbol, the Marilyn Monroe of the World War I era but still Olive's death is clouded in mystery. 

Oliva R. Duffy was born in Charleroi, Pennsylvania. She was the eldest of three children born to James and Rena Duffy, both of whom were of Irish descent. She had two brothers: James (born 1896) and William (born 1899).[3] Thomas later helped both of her brothers to secure work in the film industry; after serving in the United States Marine Corps in France during World War I, William worked as a cameraman, and James worked as an assistant director. At the time of her death, both brothers were employed by Selznick Productions.

Olivia's father, James Duffy, a steelworker, died in a work-related accident in 1906. After his death, the family moved to McKees Rocks, Pennsylvania, a small mill town. Thomas and her brothers often stayed with their grandparents while her mother Rena worked in a local factory. Rena Duffy later married Harry M. Van Kirk, a worker on the Pittsburgh and Lake Erie Railroad. The two had a daughter, Harriet, who was born in 1914 and died in a car accident in 1931.

Thomas left school at the age 15 to help support her siblings. She got a job selling gingham at Joseph Horne's department store for $2.75 per week (equivalent to $75.46 in 2019).

In April 1911, aged 16, she married Bernard Krug Thomas in McKees Rocks. During the two-year marriage, she reportedly worked as a clerk in Kaufmann's, a major department store in Pittsburgh. After their separation in 1913, Thomas moved to New York City and lived with a family member. She later found work in a Harlem department store.

Thomas began her career as an illustrator's model in 1914, and moved on to the Ziegfeld Follies the following year. During her time as a Ziegfeld girl, she also appeared in the more risqué show The Midnight Frolic. In 1916, she began a successful career in silent films and would appear in more than 20 features over the course of her four-year film career. That year she also married actor Jack Pickford, the younger brother of fellow silent-film star Mary Pickford.

Olivia and Pickford would often be separated by their careers and their marriage appeared rocky at times. After over a year of making motion pictures together in California, the couple sailed from New York City, New York to Paris, France on August 12, 1920 for a planned second honeymoon.

On the evening of September 9 1920, they went out on the town, not returning to their room until after 3am. Olive then took a large quantity of mercury bichloride which had been prescribed to Pickford, and died soon afterwards. Her remains were returned to the United States for burial.

Although her death was ruled accidental, news of her hospitalization and subsequent death were the subject of speculation in the press. Thomas' death has been cited as one of the early scandals in Hollywood that was heavily publicized.