Roscoe Conkling Arbuckle, also known as Fatty Arbuckle (March 24, 1887 – June 29, 1933), was an American silent film comedian, director, and screenwriter.

Born in Smith Center, Kansas, to Mollie and William Goodrich Arbuckle, he had several years of Vaudeville experience, including work at Idora Park in Oakland, California. One of his earliest mentors was comedian Leon Errol. He began his film career with the Selig Polyscope Company in July 1909. Arbuckle appeared sporadically in Selig one-reelers until 1913, moved briefly to Universal Pictures and became a star in producer-director Mack Sennett's Keystone Cops comedies.

Arbuckle was also a talented singer. After Enrico Caruso heard him sing he urged the comedian to "give up this nonsense you do for a living, with training you could become the second greatest singer in the world".

Despite his massive physical size, Arbuckle was remarkably agile and acrobatic. Mack Sennett, when recounting his first meeting with Arbuckle, noted that he "skipped up the stairs as lightly as Fred Astaire"; and, "without warning went into a feather light step, clapped his hands and did a backward somersault as graceful as a girl tumbler". His comedies are noted as rollicking and fast-paced, have many chase scenes, and feature sight gags. Arbuckle was fond of the famous "pie in the face," a comedy cliché that has come to symbolize silent-film-era comedy itself.

In 1914 Paramount Pictures made the then-unheard of offer of $1,000 a day/25% of all profits/complete artistic control to make movies with them. The movies were so lucrative and popular that in 1918 they offered Arbuckle a 3-year/$3 million contract.

Arbuckle is noted as one of the most popular actors of his era, but he is best remembered for a heavily publicized criminal prosecution that ended his career. Although he was acquitted by a jury with a written apology, the trial's scandal ruined the actor, who would not appear on screen again for another 10 years.