Leighton Graves Osmun (December 13, 1880 – June 12, 1928) was an American screenwriter, playwright, and author who was active during Hollywood's silent era.^[1] He often collaborated with fellow screenwriter Beatrice deMille.^[2][3]

Leighton was born in Newark, New Jersey, to banker J. Allen Osmun and Mary Graves.^[4]

In 1916, while living in Los Angeles and working as a writer, Leighton briefly disappeared after divorcing his first wife, Harriet Scholl, and marrying his second wife, Lula Dix Drummond.^[4] He and Lula had a daughter, Sarah, together; she would go on to marry William Ince, son of director Thomas H. Ince.^[5]

In the summer of 1929, he suffered a heart attack and died after rescuing a child who was in danger of drowning at a beach in La Jolla, California. He was 48 years old.^[6][7][8] He was survived by his second wife, Dix, and his daughter, Sarah.

• East Side - West Side (1923)
• The Woman Game (1920)
• The Fortune Teller (1920)
• The Clutch of Circumstance (1918)
• Treasure of the Sea (1918)
• The Claim (1918)
• The Devil-Stone (1917)
• Forbidden Paths (1917)
• The Inner Shrine (1917)
• The Jaguar's Claws (1917)
• Unconquered (1917)
• Sacrifice (1917)
• Castles for Two (1917)
• Betty to the Rescue (1917)
• The Years of the Locust (1916)
• The Heir to the Hoorah (1916)
• The Storm (1916)
• Each Pearl a Tear (1916)