Roscoe Conkling "Fatty" Arbuckle (; March 24, 1887 – June 29, 1933) was an American silent film actor, comedian, director, and screenwriter. He started at the Selig Polyscope Company and eventually moved to Keystone Studios, where he worked with Mabel Normand and Harold Lloyd as well as with his nephew, Al St. John. He also mentored Charlie Chaplin, Monty Banks and Bob Hope, and brought vaudeville star Buster Keaton into the movie business. Arbuckle was one of the most popular silent stars of the 1910s and one of the highest-paid actors in Hollywood, signing a contract in 1920 with Paramount Pictures for $14,000 (equivalent to $181,000 in 2020).

Arbuckle was the defendant in three widely publicized trials between November 1921 and April 1922 for the alleged rape and manslaughter of actress Virginia Rappe. Rappe had fallen ill at a party hosted by Arbuckle at San Francisco's St. Francis Hotel in September 1921, and died four days later. A friend of Rappe accused Arbuckle of raping and accidentally killing her. The first two trials resulted in hung juries, but Keaton testified for the defense in the third trial, which acquitted Arbuckle, and the jury gave him a formal written statement of apology.

Despite Arbuckle's acquittal, the scandal has mostly overshadowed his legacy as a pioneering comedian. At the behest of Adolph Zukor, president of Famous Players-Lasky, his films were banned by motion picture industry censor Will H. Hays after the trial, and he was publicly ostracized. Zukor was faced with the moral outrage of various groups such as the Lord's Day Alliance, the powerful Federation of Women's Clubs and even the Federal Trade Commission to curb what they perceived as Hollywood debauchery run amok and its effect on the morals of the general public. While Arbuckle saw a resurgence in his popularity immediately after his third trial (in which he was acquitted) Zukor decided he had to be sacrificed to keep the movie industry out of the clutches of censors and moralists. Hays lifted the ban within a year, but Arbuckle only worked sparingly through the 1920s. Keaton made an agreement to give him thirty-five percent of his profit from Buster Keaton Comedies Co. He later worked as a film director under the pseudonym William Goodrich. He was finally able to return to acting, making short two-reel comedies in 1932–33 for Warner Bros.

Arbuckle died in his sleep of a heart attack in 1933 at age 46, reportedly on the day that he signed a contract with Warner Bros. to make a feature film.