The film's plot is non-linear. This summary is presented in chronological order.
In 1970 in Davie, Florida, Linda Boreman and her best friend Patsy go roller skating when they volunteer to dance on stage to the local band at the roller rink. Their dancing attracts the attention of Chuck Traynor, who develops a relationship with Linda. A few weeks, later Linda invites Traynor over for dinner at her parents house where he makes a charming impression on them. However, after Linda breaks a curfew one too many times, she moves out of her fiercely religious parents' house and marries Traynor. During a party, Linda watches one of Traynor's homemade porno films for the first time.
Six months later, Linda bails Traynor out of jail after he is arrested for soliciting prostitution. Desperate for money, Traynor forces Linda into prostitution at gunpoint. Shortly afterwards, he has her audition at B&A Films in New York City, where she lands a career after Traynor shows producers Nat Laurendi and Anthony Romano an 8mm film of her doing fellatio.
Linda travels back to Florida and begins work on the film Deep Throat, where she first uses her stage name Linda Lovelace. Upon release in 1972, Deep Throat becomes a hit among viewers and critics, raking in over $30,000 in the box office on its first week. During a private screening of the film in Los Angeles, Hugh Hefner convinces Linda that she has the potential to be more than a porn actress. Following the screening, Traynor once again forces Linda at gunpoint to participate in a gang bang at a hotel.
The next day, she secretly meets up with Romano and tells him she wants out of the porno business, revealing the facial bruises inflicted by Traynor. Sympathetic to Linda, Romano has her checked in to a hotel while he and his bodyguards whip and beat up Traynor for abusing Linda and for the $25,000 he owes for the production costs.
Six years later, following her divorce from Traynor, Linda marries Larry Marchiano and moves to Long Island and has a son with him. She takes a polygraph test prior to publishing her autobiography 'Ordeal', which details her years of Traynor physically and sexually abusing her, as well as controlling all of her earnings. Linda appears on Donahue to talk about her autobiography, with her distraught parents breaking down in tears while watching her on TV. A few days later, the Marcianos travel to Florida for Linda to reconcile with her parents.
The film's ending captions reveal that while Deep Throat made over $600 million worldwide, Linda earned only $1,250. 'Ordeal' went on to sell out three printings, and for 20 years, Linda had spoken out against pornography and domestic violence. Traynor went on to marry Marilyn Chambers. Linda died at the age of 53 from injuries sustained in a car accident in 2002. Traynor died from a fatal heart attack three months later.