She was born in Strichen, Aberdeenshire, in Scotland, in 1886, the daughter of the plasterer Charles Low, a socialist and avowed atheist. In 1907 she met William Hebditch, a commercial traveller from Yorkshire who had stayed at the hotel run by her parents; the two were secretly married in Aberdeen and shortly after the couple left Scotland for Alberta in Canada, where Lorna Moon gave birth to her first child, William Hebditych (1908–1990), in 1908. In 1913 she left Hebditch and fell in with Walter Moon, with whom she had a child, Mary Leonore Moon (1914–1978), in 1914. She and Walter travelled to Winnipeg, where she began working as a journalist and where she adopted a pen-name closer to her literary inspiration, Lorna Doone. An anecdote tells how she contacted Cecil B. DeMille and offered a critical appraisal of the screenplays of the day. He challenged her to come to Hollywood and write them herself if she thought she could do better; and by 1921 she did just that, working as a script girl and screenwriter. During her career in Hollywood she had a third child by Cecil B. DeMille’s brother William. This child, Richard, grew up unaware of his mother’s identity; in later years he discovered his parentage and wrote the memoir My Secret Mother, Lorna Moon. Lorna Moon contracted tuberculosis and died in a sanatorium in Albuquerque, New Mexico, in 1930, aged 44. She was cremated and her ashes were returned to Scotland, to be scattered on Mormond Hill near Strichen.
Her screen credits include The Affairs of Anatol (1921), Don't Tell Everything (1921), Her Husband's Trademark (1922), Too Much Wife (1922), Upstage (1926), After Midnight (1927), Women Love Diamonds (1927), Mr. Wu (1927), and Love (1927).
Her literary works include Doorways in Drumorty (1925), a collection of short stories, and the novel Dark Star (1929). Dark Star was a critical success, and in 1930 was adapted for the screen as Min and Bill, starring Marie Dressler and Wallace Beery. Doorways in Drumorty contained a series of stories set in a fictional Scottish town: however the location and characters were drawn from her memories of Strichen, much to the indignation of certain of the townspeople, and her work was banned from the local library.
The Collected Works of Lorna Moon, edited by Glenda Norquay, was published in 2002. In 2008 a plaque commemorating Lorna Moon was unveilied in Strichen. In 2011 a stage play, based on the stories in Doorways in Drumorty, was written by Mike Gibb and performed around Scotland by Red Rag Theatre. A film based on the life of Lorna Moon, scripted by Alison Peebles, has been proposed, with Kate Winslet being named as a potential candidate to play the title role.
- "Lorna Moon - Biography". IMDb. Retrieved 2017-09-03.
- Richard DeMille (1998). My Secret Mother, Lorna Moon. New York: Farrar Straus & Giroux. ISBN 0374217572.
- "The Far Side of Lorna Moon". ASLS. Retrieved 2012-03-21.
- "Overview of Lorna Moon". Gazetteer for Scotland. Retrieved 2012-03-21.
- "Doorways in Drumorty shines light on the incredible life of Lorna Moon". The Courier. Dundee. 2011-09-12. Retrieved 2012-03-21.
- Glenda Norquay (eds) (2002). The Collected Works of Lorna Moon. Edinburgh: Black and White Publishing. ISBN 1902927362.
- "Winslet targeted to shine as Moon". BBC News. Glasgow. 2009-10-20. Retrieved 2012-03-21.